In fact, the qrscanner plug-in is not a big problem. The only problem is that on some mobile phones, the camera preview cannot be started when it is first opened. To be exact, the camera preview has been opened, but it is blocked by a layer of white. After a long time of research, no reason has been found, but the solution has been figured out, that is to call the camera preview Destroy the code scanning function once before.
The code is as follows:

//Scan payment
    $("#scan-text").html("Scan");
    if (typeof QRScanner != "undefined") {
        // Get and scan code if you don't have permission
        QRScanner.prepare(onDone);
    } else {
        // Request permission failed
        weihuan_tips("Scan code failed to load...", "center", 2000);
    }

    function onDone(err, status) {
      //Destroy once before starting
        QRScanner.destroy();
        if (err) {
            console.error(err);
        }
        //If you get permission
        if (status.authorized) {
            // Start scan code
            $("body").css({
                background: "transparent"
            });
            QRScanner.scan(displayContents);
            $("#scan-text").html("Scanning code...");

            function displayContents(err, text) {
                // Scan code failure
                if (err) {
                    weihuan_tips("Start scanning code error...", "center", 2000);
                } else {
                    // Successful scan code
                    app.dialog.progress();
                    var scan_user_id = localStorage.getItem("user_id");
                    var rece_user_id = GetUrlPara("user_id", text);
                    var type = GetUrlPara("type", text);
                    if (type == 2) {
                        $.ajax({
                            url: api + "scan-success.php",
                            data: {
                                type: type,
                                scan_user_id: scan_user_id,
                                rece_user_id: rece_user_id
                            },
                            type: "POST",
                            async: true,
                            timeout: 5000,
                            dataType: "json",
                            success: function(data) {
                                if (data.code == 200) {
                                    app.dialog.close();
                                    $("#scan-text").html("Scanning code successfully");
                                    homeView.router.navigate("/scan-pay/", {
                                        context: {
                                            ID: data.ID,
                                            user_id: rece_user_id,
                                            user_name: GetUrlPara("user_name", text)
                                        }
                                    });
                                } else {
                                    app.dialog.close();
                                    QRScanner.prepare(onDone);
                                }
                            }
                        });
                    }
                }
            }
        } else {
            // Without
            weihuan_tips(
                "Please give the app permission with camera...",
                "center",
                2000
            );
        }
    }