The convenience of “no installation, available at your fingertips” of the WeChat small program makes it unique in the application of mobile terminal auxiliary experimental teaching. In order to optimize the assessment system and improve the quality and outcomes of experimental teaching, a self-designed WeChat small program was used to assist the development of the process assessment system. This system was applied to the teaching practice of “Experiment of Inorganic Chemistry” course for the first-year undergraduates majored in Biological Engineering, with the aim to promote teaching and learning by assessment. The results showed that course scores of the students who used this small program were superior to the control group and the correlation between the process assessment and final examination results was significant. These results indicated the WeChat small program assisted process assessment could effectively improve the learning outcomes of students, enable them to grasp the knowledge of Experiment of Inorganic Chemistry efficiently. The results of the questionnaire for the teachers and students also showed a high recognition of the WeChat small program assisted teaching.