The invention provides a visceral fat determination device and a detection method and belongs to the technical field of human body information measurement. The visceral fat determination device comprises an input unit, a calculation control unit, an output unit, a light-emitting unit, a light detection unit, a signal processing unit and a display unit. The calculation control unit is connected with the output unit, the signal processing unit, the input unit and the display unit respectively, the output unit is connected with the light-emitting unit and the signal processing unit, and the input unit is used for inputting human body measurement information. The calculation control unit outputs a control signal, is driven by the output unit and then controls the light-emitting unit to emit light, the light enters the position to be determined of the human body, reflected light is detected by the light detection unit, the signal processing unit performs amplification and filtering, and the calculation control unit calculates body fat mass, visceral fat mass and whole-body subcutaneous fat mass according to a set mathematic model. According to a calculation method, visceral fat mass is obtained by subtracting whole-body subcutaneous fat mass from the body fat mass. The visceral fat determination device is simple, accurate in determination and convenient to operate.