With rapid development of the Internet, big data, and cloud computing, machine translation has undergone tremendous changes, which gives birth to machine translation post-editing (MTPE) model and helps it to be the mainstream model in translation service industry. However, further improvement of the efficiency and quality of MTPE also needs implementation of corresponding specifications and guidelines, so as to help post-editors identify errors in machine translation and decide whether it needs to be edited. This article introduces the MTPE guidelines by TAUS (the Association of Translation Automation Users) which guides the light post-editing (LPE) practice of a medical report, analyzes existing problems during the post-editing process, and evaluates the significance of the guidelines.