The blast resistance of precast concrete (PC) slabs was studied by blast test. The blast test of PC slab under different scaled distance (1m/kg1/3, 0.8m/kg1/3 and 0.6m/kg1/3) blast was conducted, and the incident and reflected overpressure, displacement and damage distribution of PC slab were measured. The results were compared with the test results of ordinary reinforced concrete (RC) slabs at the same scaled distance. The results showed that the incident and reflection overpressure were consistent with the CONWEP empirical formula, which verified the effectiveness of the blast load in the test. Under the same working condition, the maximum displacement of PC slab was greater than that of RC slab. When the scaled distance is larger than 0.6m/kg1/3, the residual displacement of PC slab is larger than that of RC slab, and when the scaled distance is 0.6m/kg1/3, the residual displacement of PC slab is smaller than that of RC slab. PC slab can dissipate the blast shock wave evenly. No obvious cracks are observed in the laminated surface of the PC slab, thereby meeting the shear resistance requirements. By combining SDOF method and test method, the stiffness reduction coefficient (δ = 0.9) was proposed to predict the dynamic response of PC slab.