In order to monitor the working state of a control cell of drift angle for an optical remote sensor and to test its function, performance and reliability, a closed-loop test method for the controlling cell of adjusting drift angle in real time was given. Using this method and the computer technology, a testing system was designed to analyse the controlling signals and form the information of a coder by the control tactic of drift angle. Then, the information of the simulation coder was feedbacked to the controlling cell to realize the tests for the control tactic, driving ability and the error disposal. The controlling cell of adjusting drift angle was tested in a work frequency of 1.2 kHz, a least interval of coder feedback of 10 ms and the warp of feedback less than ±1 code. The experimental results show that the testing system can exactly monitor the working state of the controlling cell of drift angle for the remote sensor and can cover the entire path in the control tactic,which totally satisfies the requirements of the controlling cell of drift angle for closed-loop and real time testing.