The invention provides a light fixture testing device. The light fixture testing device includes a testboard and a test display device, wherein car light holder fixing pedestals and car light socketsare arranged on the upper end surface of the testboard; a first shading cylinder is arranged on the car light holder fixing pedestals; a car light high and lower beam switching switch is arranged on the upper end surface of the testboard and approaches to the car light holder fixing pedestals; a track plate is also arranged on the upper end surface of the testboard; the track plate is a steel plate; a magnetic base is arranged on the track plate; a second shading cylinder is arranged on the magnetic base; universal connecting pipes are arranged at the side edges of the testboard; an observation mirror is arranged at one end of the each universal connecting pipe; the light emitting situation of each location of the car lights on the car light holder fixing pedestals can be observed by meansof the first shading cylinder and by adjusting the steering angle of the observation mirrors on the universal connecting pipes; and the light emitting situation of each location of the car lights inthe second shading cylinder can be observed by adjusting the relative position of the magnetic base on the track plate and by adjusting the steering angle of the observation mirrors on the universal connecting pipes at the same time.