In the second production phase of Fuling shale gas field, the difficulties in fracturing treatment came along with the increasing buried depth, especially under the condition of only 93MPa limited pressure for equipments, acid reducing effect was not obvious in high pressure in deep well construction, which severely restricted the implementation of the later fracturing measures. By the analysis on the main causes of unsatisfactory acid reducing effect, the main factors affecting the acid treatment effect are studied through indoor and field tests on this basis. The tests show that the increase of acid treatment displacement, the increase of acid concentration and reasonable optimizing the amount of acid are helpful to improve the acid treatment effect. The optimization suggestions are put forward, which has important significance to the later fracturing construction of deep shale gas well in Fuling shale gas field.