执行块: 
 
splash = QtWidgets.QSplashScreen(QtGui.QPixmap("img.png"))
splash.showMessage("加载... 0%", QtCore.Qt.AlignHCenter, QtCore.Qt.black)
splash.show()
window = MyWindow()
window.load_data(splash)  # 加载数据
splash.finish(window)  # 隐藏启动界面 
Splash页面信息显示:
 
    def load_data(self, sp):
        for i in range(1, 11):              #模拟主程序加载过程
            time.sleep(0.5)                   # 加载数据
            sp.showMessage("加载... {}%".format(i * 10), QtCore.Qt.AlignHCenter |QtCore.Qt.AlignBottom, QtCore.Qt.black) 
注意事项:
 
 
 
 from PyQt5.QtWidgets import QMainWindow,QDialog,QWidget,QMessageBox
 
 更换默认的object,可继承上述四个基类(继承QMessageBox可在类中直接使用该控件)