In order to improve the adsorbing lauric acid capacity for steel slag，HF solution was applied as corrosion solution，of which effect on the pore structure，phase composition，microstructure，and the absorbing lauric acid capacity of steel slag were investigated.Then，the modified steel slag was compounded with lauric acid，and other raw materials such as Portland cement were introduced to prepare phase change concrete materials.The fluidity，cohesion，and water retention of concrete mortar were analyzed，and the effect of hydration heat of phase change concrete on the early compression strength of concrete was studied.The results showed that the addition amount of HF solution significantly affected the adsorbing lauric acid capacity of steel slag.When the adding amount of HF solution was 5.0%（mass fraction），the modified steel slag could adsorb 24.12% lauric acid.The melting and condensation temperatures of composite samples were 28.6 ℃ and 30.9 ℃ respectively，and the latent heats of melting and condensation reached 43.6 and 43.7 J/g，respectively.Steel slag based concrete adsorbed with lauric acid had good fluidity，cohesiveness and water retention.The peak temperature and the time needed to reach the peak temperature for the concrete could be reduced because of phase change heat storage，which endowed concrete products with a higher early compression strength.This study provided a new idea for the preparation of new concrete material for thermal insulation.