The invention discloses a method for improving an oil reservoir exploitation effect by utilizing discrete fracture endpoint deformation numerical simulation. The method comprises the following steps of dividing an oil reservoir storage body into a continuous medium and a discrete medium according to a characteristic scale; deforming the end part of a discrete fracture from a square shape into a pointed shape to eliminate tiny grids, establishing rock stratum surface grids, and establishing three-dimensional oil reservoir grids; inputting measured oil reservoir parameters such as porosity, permeability and water saturation into a simulator, wherein a real value rather than a grid display value is used for the width of the discrete fracture; correcting the oil reservoir parameters by using a history matching method; and measuring and calculating the well productivity, residual oil and gas reserves and the distribution positions of residual oil and gas, and making a subsequent oil reservoir exploitation plan. According to the method, a discrete fracture numerical simulator can be prevented from measurement and calculation interruption and failures, the whole links of oil reservoir exploitation can be actually measured and calculated to improve the measurement and calculation accuracy of the well productivity and the residual oil and gas distribution of an oil reservoir, and a more effective development plan can be made to improve the oil reservoir exploitation effect.