Due to the low permeability and porosity, effective development of tight gas reservoirs relies on hydraulic fracturing. During fracturing, the fracturing fluid enters into pore and pore throat, which can create water blockage therein and decrease the well productivity. Adding additive in the fracturing fluid is an effective method to reduce the water blockage. In order to find out the mechanism behind this method, several experiments were conducted; the DME micro-emulsion was taken as the additive. Firstly, surface tension test was conducted to acquire the relationship between the concentration of additive and surface tension, thus to obtain the optimal usage of additive. Secondly, the contact angle test was conducted to test the wettability alteration by the DME micro-emulsion. Thirdly, imbibition and permeability recovery tests were conducted to test if the DME could reduce the water blockage. Moreover, the distribution of water in large and small pores were obtained through the nuclear magnetic resonance (NMR). In this paper, a systematic method was established to screen the additive for reducing the water blockage during hydraulic fracturing. Meanwhile, the key properties of such type of additive was revealed.