The invention relates to an intelligent car-finding service system in a parking lot, comprising a parking space terminal system distributed in each parking space, and a car-finding service end system connected with the parking space terminal system. The parking space terminal system includes a parking space detector, a parking space camera, a parking space status indicator light, a processor module, and a communication module; Inquiry terminal, and QR code for car search service. The invention also relates to a working method of an intelligent car search service system in a parking lot. The steps include: detecting the state of the parking space and extracting the license plate information, establishing the mapping relationship between the license plate number and the parking space, scanning the QR code to obtain the server website and the current location of the car owner, and inputting the license plate No., plan and guide the route map, send it to the user terminal, and release the mapping relationship between the license plate number and the parking space. The invention is easy to realize, does not need to increase the cost of the car owner, and has zero verification of the car owner's information, can effectively solve the problem of "difficulty in finding a car", and has strong practical application value.