Disclosed is an indoor air humidity calculation method, comprising: during an operating process of an air-conditioner (10), collecting an outdoor temperature, an indoor temperature and an indoor coil pipe temperature (S1); calculating a calculated temperature difference (S2); successively carrying out indoor environment temperature compensation, outdoor environment temperature compensation, indoor wind speed compensation and outdoor wind speed compensation on the calculated temperature difference so as to obtain a compensation temperature difference ΔT' (S3); and invoking a real-time compressor frequency which is fed back, and using the real-time compressor frequency and the compensation temperature difference ΔT' to calculate a real-time humidity Rh_s (S4). Also disclosed is an air-conditioner (10). Where no humidity sensor needs to be added, the air-conditioner (10) uses a sensing device thereof to calculate the humidity of a room under the current operating condition so as to prepare for follow-up control. Moreover, in a calculation process, an algorithm design overcomes the impact of an indoor temperature, an outdoor temperature, an indoor wind speed and an outdoor wind speed on humidity.