Porous materials are known for the large number of pores in their interior, which have a large specific surface area and are often used in catalysts. Moreover, high-entropy alloys have both high strength and high toughness because of their unique structure. In this paper, a porous high-entropy FeCoCrNi alloy was prepared by sparking plasma sintering (SPS) with sodium chloride (NaCl) as the space holding material. The effects of different parameters, such as porosity, pore size and sintering time, on the mechanical properties of porous FeCoCrNi high-entropy alloys were investigated. The pore size is determined by the size of the sodium chloride. With increasing sodium chloride content, the porosity of the alloy increases, and the compressive strength decreases. At the same porosity, the compressive strength of the alloy increases with decreasing pore size. A compressive strength of 158 MPa is obtained for the sample with a porosity of 30% and a pore size of 50 μm at an SPS temperature of 650 ℃ and a holding time of 40 min. In addition, secondary sintering (1 100 ℃) can effectively improve the compressive strength of porous materials, and the longer the sintering time is, the better the lifting effect. The compressive strength of the sample with 30% porosity and 50 μm pore size reaches 656 MPa after 90 min of secondary sintering.