The invention discloses a body composition, mental stress and arteriosclerosis synchronous detection device which comprises a bioelectrical impedance measuring component, a pulse oximeter signal measuring component, a body weight measuring module, a height measuring module, a signal processing unit and a main control unit. The signal processing unit applies sinusoidal current to human limbs through current electrodes and acquires bioelectrical impedance signals, pulse oximeter signals and body weight and height signals obtained by synchronous measurement of the bioelectrical impedance measuring component, the pulse oximeter signal measuring component, the body weight measuring module and the height measuring module, processes the signals and transmits the processed signals to the main control unit; the main control unit receives the corresponding signals processed by the signal processing unit and analyzes the signals to obtain body compositions, mental stress quantization values, arteriosclerosis degree and height and body weight values. The physical health state, the mental health state and the vascular health state of a testee can be rapidly, simply and conveniently acquired byone-step measurement.