Generally，elastoplastic reservoirs have threshold pressure gradients and pressure-sensitive effects that can change the permeability during development. Therefore，their flow characteristics and the effective production laws of reserves are dramatically different from those of conventional reservoirs，and the design methods for conventional well patterns and spacing cannot meet the actual development requirements. Based on the traditional mechanics of fluid flow in porous media，a flow model considering the influence of the pressure-sensitive effects and threshold pressure gradients was built with the typical injection-production well pattern，and the distribution law of injection-production flow fields was obtained using the steady successive substitution method. According to the characteristics of elastoplastic reservoirs，an evaluation method for the effective production effect of reserves was proposed，and the effective production limit of reserves under different conditions was obtained. The results show that the production range and effective production intensity of reserves in injection-production units have obvious changes under the influence of pressure sensitivity and threshold pressure gradients. In given reservoir development conditions，the limit of effective reserve production is determined，and the change chart of inject-production well spacing that can achieve the target of effective reserve production is obtained through calculation，providing a theoretical basis for the optimization design of well patterns in oilfields.