步骤1：

修改sTargetPicPath图片路径为自己图片的路径，先运行如下代码，得到图片的base64格式的图片码值

import base64
sTargetPicPath = r'C:\Users\user\Desktop\1.jpg'
with open(sTargetPicPath, 'rb') as open_icon:
    b64str = base64.b64encode(open_icon.read())
    print(b64b64str)

步骤2：

修改b63img的值为步骤1得到的值，运行如下代码例子，设置应用图标，大功告成。

import tkinter as tk
from base64 import b64decode
from PIL import Image, ImageTk

window = tk.Tk()
window.title("test")
window.geometry("420x200+0+0")

b64img = b'xxx'
icon_img = b64decode(b64img)
icon_img = ImageTk.PhotoImage(data=icon_img)
window.tk.call('wm','iconphoto',window,icon_img)

if __name__ == "__main__":
    window.mainloop()