• multiprocessing对象要放在__main__所在的启动文件
• 使用槽连接multiprocessing对象

import sys
from multiprocessing import Pool

from PyQt5.QtWidgets import *


class Window(QWidget):

    def __init__(self):
        super().__init__()
        self.setWindowTitle("hello")
        self.resize(800, 600)
        self.btn = QPushButton('Start')
        self.setup_ui()

    def setup_ui(self):
        layout = QVBoxLayout()
        self.setLayout(layout)
        layout.addWidget(self.btn)


def updater(num):
    print(num)


def main_tracker():
    p = Pool(processes=4)
    p.map(updater, range(0, 100))
    p.close()
    p.join()


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = Window()
    # 建立槽连接
    window.btn.clicked.connect(main_tracker)
    window.show()
    sys.exit(app.exec_())