依赖：pip install Pillow

from PIL import Image, ImageDraw, ImageFont, ImageFilter
from random import randint, choice


# 随机ASCII码生成数字或大小写字母
def rnd_char():
    return chr(choice([randint(48, 57), randint(65, 90), randint(97, 122)]))


# 背景颜色
def rnd_color():
    return randint(64, 255), randint(64, 255), randint(64, 255)


# 验证码颜色
def ran_color2():
    return randint(32, 127), randint(32, 127), randint(32, 127)


num = 5  # 生成num位的验证码
width = 50 * num  # 图宽
height = 60  # 图高
image = Image.new('RGB', (width, height), (255, 255, 255))

# 创建Font对象 .tff为字体文件 可自定义
font = ImageFont.truetype("Arial Black.ttf", 50)
# 创建Draw对象
draw = ImageDraw.Draw(image)
# 填充每个像素
for x in range(width):
    for y in range(height):
        draw.point((x, y), fill=rnd_color())
# 生成验证码
for k in range(num):
    draw.text((50 * k + randint(1, 10), randint(0, 5)), rnd_char(), font=font, fill=ran_color2())
# 对图片进行模糊处理
image = image.filter(ImageFilter.GaussianBlur)
image.save('rndcode.jpg', 'jpeg')

效果图:

code.jpg