The utility model belongs to the technical field of dehydration of oil fields and particularly relates to a skid-mounted crude oil dehydrating device. The skid-mounted crude oil dehydrating device comprises a three-phase separator, wherein a skid seat is arranged below the three-phase separator; a water chamber liquid level transmitter is arranged in a water chamber of the three-phase separator; a water chamber electric control valve is arranged at the lower part of the water chamber; an oil chamber liquid level transmitter is arranged in an oil chamber of the three-phase separator; an oil chamber electric control valve is arranged at the lower part of the oil chamber; a pressure transmitter and a safety valve are arranged at the top of the three-phase separator. The skid-mounted crude oil dehydrating device integrates with the functions of dehydrating, degassing and data detecting of oil well production liquid; all parts are integrated on a skid block; through the adoption of the integrated skid-mounted structure, the functions are integrated; the device is small in occupied area and convenient to operate and manage; the problems of long construction period and large occupied area of the oil field production liquid dehydrating device are solved.