The invention provides a detector. The detector comprises a Pipad, a first WiFi card and a second WiFi card, wherein at least two card slots are formed in the Pipad; the first WiFi card and the second WiFi card are respectively placed on the Pipad through the card slots; the Pipad is provided with a first software module; the first software module drives the first WiFi card to perform WiFi network MAC layer detection operation under the control of a control module and acquires a detection result; and the second WiFi card is driven to transmit the detection result to a mobile intelligent terminal. The WiFi cards on the Pipad are driven to detect a WiFi network MAC layer, the detection result is transmitted to the mobile intelligent terminal, and the purpose of reporting a detection value of a parameter of the detected WiFi network MAC layer is achieved. The Pipad and the mobile intelligent terminal are low in cost, small in size and light in weight, the detection cost is reduced obviously, and the detector is convenient to carry and use for a user.