Aiming at the problem that the fiber Bragg grating(FBG) strain gauge cannot accurately measure the strain in multiple directions on the structure simultaneously, a threeway surface strain gauge based on FBG has been designed in this paper. The gauge adopts the circular base structure, and three FBG fibers at a certain angle are encapsulated on the base, which is suitable for the synchronous measurement of strain in three directions. Furthermore, the performance of the packed strain gauge is investigated and the comparison test with resistance strain gauge is designed. The results show that the strain gauge has good linearity, the maximum hysteresis error is 6.1%, and the sensitivity increases about 2.3 times and 1.4 times at 0° and 90° respectively. With the increase of load, the measurement error decreases gradually and is controlled within ±5% when the load is greater than 1.5 kg.