The invention provides a PTB cementitious capillary crystalline waterproofing material and a use method thereof, belonging to the technical field of building materials. The PTB cementitious capillary crystalline waterproofing material comprises a PTB water solution and PTB special powder. The use method comprises the steps of: cleaning a base layer, and spraying water for wetting; preparing the PTB cementitious capillary crystalline waterproofing material; constructing the PTB cementitious capillary crystalline waterproofing material; and maintaining. The invention solves the leakage difficulty puzzled for a long time by people and the problem of poor property of the traditional waterproofing coating. The waterproofing material has better bonding, waterproofing and ventilating properties,can overcome the defect of the traditional cementitious capillary crystalline waterproofing material, is suitable for massive popularization and application, and has remarkable economic benefit and social benefit.