The effect of activated coal gangue powder （ACGP） on the capillary water absorption property of concrete under different contents and water-binder ratios in freeze-thaw environment was studied， and the prediction model of relative water content distribution of activated coal gangue powder concrete （ACGPC） was established based on unsaturated capillary theory. The results indicate that the freeze-thaw action gradually increases the cumulative water absorption and absorptivity of ACGPC gradually enhances， the capillary water absorption performance reduces and the water intrusion depth increases. With the same content of ACGP， the capillary water absorption resistance of ACGPC lowers with the increase of water-binder ratio. When the water-binder ratio is constant， the cumulative water absorption and capillary absorptivity of ACGPC reduces and then rises with the increase of ACGP， which refines the harmful pores and improves the pore size distribution in concrete at proper content of ACGP， with the most significant effect at 20%.