Abstract: Astronomical dome is an important peripheral of optical telescope system, with the development of the telescope technology, astronomical dome control technology has also been improved. In order to realize the full automation of Yunnan observatory Automatic Differential Image Motion Monitor(ADIMM), an astronomical dome control system based on ASCOM and Modbus/TCP protocol is developed. Combined with ASCOM astronomical technical standard and the Modbus/TCP protocol specification, the control system structure principle and realization method of Yunnan observatory ADIMM astronomical dome control system is introduced in detail. The measured results show that the dome control system has good stability and compatibility, which fully meets the requirements of ADIMM automatic observation, and it provides a reference of experience and methods for the designs of the small and medium-sized astronomical telescope dome.