As computer information science technology and software technology advances, the acquisition and use of soft-ware have become very convenient and available, but software piracy has become commonplace. 66% of software piracy was used in China alone in 2017, resulting in a loss of at least $6.8 billion to enterprises, according to the BSA. So how to protect our intellectual property while enjoying the convenience of software is a problem for every developer. One way to alleviate this problem from a technical perspective is to use software protection techniques, especially the obfuscation of code. The most common and prominent of the obfuscation techniques is control flow obfuscation. There are many studies of source code and bytecode obfuscation. However, research on Micropython bytecode obfuscation is quiet rare. In this paper, we propose a Micropython bytecode obfuscator based on control flow obfuscation, which has the advantage of being efficient and convenient, and we have implemented and experimented on the STM32L4 platform. The test results prove that the obfuscator can greatly increase the difficulty of cracking Micropython bytecode.