The invention discloses a beverage bottle cap with self-cooling device and a beverage bottle thereof, wherein the beverage bottle cap comprises an annular cover body, a top cover and a self-cooling device; the top cover is provided with a ventilation hole I, a ventilation hole II and a straw hole which penetrate through the top surface of the top cover; the self-cooling device comprises a fan-shaped sealing plate, a three-way control valve, a refrigerant storage container, a refrigerant output pipe and an elastic suction pipe. The beverage bottle cap with the self-cooling device adopts the waythat the control valve core of the three-way control valve is driven by the rotary fan-shaped sealing plate, in the state of self-cooling, on the one hand the beverage bottle body can achieve internal and external connection through the ventilation hole I, and on the other hand the bottom of the liquid level of the beverage entering the beverage bottle body can be heat-absorbed and vaporized, andthe temperature of the beverage is reduced; in the state of drinking, on the one hand the beverage bottle body can achieve internal and external connection through the ventilation hole II, and on theother hand directly drinking can be achieved without opening the bottle cap, resolving the problem that the refrigerant accelerates to evaporate, which is particularly suitable for containing the antipyretic beverage in summer.