Daqing Oilfield is rich in low permeability reservoirs. In order to fully understand the development dynamics of ultra-low permeability reservoirs, this paper takes Daqing Oilfield as an example and studies the productivity dynamics of fractured horizontal Wells by numerical simulation method. The results show that the productivity of fractured horizontal Wells decreases exponentially with the decrease of formation permeability. The productivity of fractured horizontal well increases with fracture length and decreases with fracture spacing. With the increase of formation coefficient and reservoir thickness, the productivity increase of fractured horizontal Wells decreases. In the case of small well spacing, the smaller the formation coefficient and reservoir thickness, the higher the productivity of fractured horizontal Wells. Compared with conventional vertical Wells, fractured horizontal Wells have better production performance.