Abstract: This study focuses on the demand for ceramic materials combining high porosity and high strength in the field of high-temperature insulation. Using high-entropy perovskite (Ca_0.4Sr_0.4Ba_0.2)(Fe_0.5Co_0.5)O₃ as the matrix and corn starch as the pore-forming agent, a series of porous high-entropy ceramics were prepared through pressureless sintering process. Effects of the mass fraction of pore-forming agent on the phase composition, microstructure, shrinkage behavior, and mechanical properties of ceramics were systematically investigated using XRD, SEM, and mechanical properties testing. The results showed that all samples might form a single-phase perovskite solid solution without impurity precipitation after sintered at 1 150 ℃, demonstrating excellent high-temperature phase stability. With the increase in mass fraction of pore-forming agent, the porosity of ceramics significantly increased from 2.2% to 37.9%, while the density decreased from 4.47 g/cm³ to 3.08 g/cm³. The microstructure evolves from a dense state into porous architecture featuring three-dimensional interconnected pores. Although the increase in porosity led to overall decline in mechanical properties of the ceramics, when the mass fraction of pore-forming agent was 15%, the sample could still maintain good comprehensive mechanical properties with flexural strength of 35.2 MPa, compressive strength of 111.96 MPa and hardness of 137.75HV1, demonstrating a good synergistic effect between high porosity and high strength. This study provides an experimental reference for the development of high-entropy thermal insulation ceramics with both lightweight and good load-bearing capacity.