You try this way. I think so.

import sys
from PyQt5.QtWidgets import QApplication
from PyQt5.QtCore import Qt

# ??t các thu?c tính DPI **tr??c** khi t?o QApplication
QApplication.setAttribute(Qt.AA_EnableHighDpiScali ng, True)
QApplication.setAttribute(Qt.AA_UseHighDpiPixmaps, True)

app = QApplication(sys.argv)