Abstract: Aiming at the drawbacks of conventionally sintered porous steels, such as random pore distribution, severe stress concentration, and poor energy-absorption stability, the powder-tube bonded array porous steels were fabricated by additive-free sintering using spherical 316L stainless steel powders and thin-walled 316L steel tubes. The effects of solution treatment with different holding time on phase evolution, microstructure, and anisotropic compressive properties were investigated. The results show that, the σ phase and Cr-rich M₂₃C₆ secondary phases precipitate in as-sintered specimens, leading to Cr depletion in austenite matrix and compressive performance deterioration. Solution treatment at 1050 ℃ promotes the re-dissolution of Cr-rich secondary phases into austenite matrix. The secondary phases are almost completely dissolved at the holding time of 30 min, whereas the re-precipitation occurs when holding time further increases to 45 min and 60 min. The powder-tube metallurgically bonded array structure combined with appropriate solution treatment can effectively improve the compressive load-bearing and energy-absorption performance of porous steel. The prepared porous steels exhibit the obvious compressive anisotropy, and the load-bearing and energy-absorption capacities under out-of-plane compression are superior to those under in-plane compression. The specimen solution-treated at 1050 ℃ for 30 min achieves the optimal comprehensive compressive properties. Compared with the as-sintered samples, the plateau stress, total energy absorption, and specific energy absorption under in-plane compression increase by 51.04%, 31.92%, and 25.00%, respectively; the corresponding increments under out-of-plane compression are 40.65%, 55.24%, and 30.85%.