您需要使用QDialog并使用exec对其进行显示，这将阻塞应用程序的其余部分，直到将其关闭。返回值exec还告诉您是否在不提交更改（即取消）的情况下关闭了表单。

这是一个简单的演示脚本，显示了如何使用QDialog：

from PyQt4 import QtCore, QtGui

class Dialog(QtGui.QDialog):
    def __init__(self, parent=None):
        QtGui.QDialog.__init__(self, parent)
        self.checkbox1 = QtGui.QCheckBox('Option one', self)
        self.checkbox2 = QtGui.QCheckBox('Option two', self)
        self.buttonOk = QtGui.QPushButton('Ok', self)
        self.buttonOk.clicked.connect(self.accept)
        self.buttonCancel = QtGui.QPushButton('Cancel', self)
        self.buttonCancel.clicked.connect(self.reject)
        layout = QtGui.QGridLayout(self)
        layout.addWidget(self.checkbox1, 0, 0, 1, 2)
        layout.addWidget(self.checkbox2, 1, 0, 1, 2)
        layout.addWidget(self.buttonOk, 2, 0)
        layout.addWidget(self.buttonCancel, 2, 1)

class Window(QtGui.QMainWindow):
    def __init__(self):
        QtGui.QMainWindow.__init__(self)
        widget = QtGui.QWidget(self)
        layout = QtGui.QVBoxLayout(widget)
        self.button = QtGui.QPushButton('Show Dialog', self)
        self.button.clicked.connect(self.handleButton)
        layout.addWidget(self.button)
        self.setCentralWidget(widget)

    def handleButton(self):
        dialog = Dialog(self)
        if dialog.exec_() == QtGui.QDialog.Accepted:
            print('Option one: %s' % dialog.checkbox1.isChecked())
            print('Option two: %s' % dialog.checkbox2.isChecked())
        else:
            print('Cancelled')
        dialog.deleteLater()

if __name__ == '__main__':

    import sys
    app = QtGui.QApplication(sys.argv)
    window = Window()
    window.setGeometry(500, 300, 200, 100)
    window.show()
    sys.exit(app.exec_())