The tip clearance measurement system can accurately measure the spacing between the engine blade and the turbine shell. One of the measurement methods is phase method, calculating the phase difference between emission signal and echo signal to solve the tip clearance. The precision of the system is closely related to the performance of synchronous acquisition. The better the synchronization performance is, the smaller the measurement error is. This paper introduces the principle of the tip clearance measurement system and analyzes the requirements of synchronous acquisition. On the basis of that, the design emphasis is analyzed and the implementation method of the synchronous acquisition control technology is demonstrated in detail. Then a tip clearance measurement system is given which is based on the synchronous acquisition control technology. Numerous tests have shown that micron-order measurement accuracy has achieved.