The invention provides a water drinking reminding method and system for wearable device, which is used to solve the problem that the existing wearable device cannot reasonably remind people of drinking water regularly according to different human body conditions and external environmental factors. The method includes: S10: acquiring current environmental information and sending the current environmental information to a mobile terminal to determine the total water drinking amount; S20: acquiring state information of a user, and accumulating the corresponding water drinking amount according tothe state information for the single required water drinking amount; S30: determining if the single required water drinking amount exceeds a preset threshold, reminding the user of drinking water andupdating the single required water drinking amount and the total water drinking amount if so, and performing the step S20 if not; and S40: determining if the total water drinking amount of the user onthe day reaches the total water drinking amount, no longer accumulating the single required water drinking amount and prompting that the total water drinking amount reaches the standard if so. The water drinking amount of the user is determined according to the acquired the state of the user, the method can reasonably remind the user of drinking water regularly and quantitatively, and the purposeof healthy living can be achieved.