The utility model belongs to the technical field of photoelectric detection, and particularly relates to an optical fiber tester. A single-channel test interface is adopted for an existing optical fiber tester. In order to overcome the defect that different interfaces need to be tested by replacing different adapters in the prior art, the utility model adopts the following technical scheme: the optical fiber tester comprises a light source device and a testing device, the light source device is a multi-channel output light source device, and a plurality of channels of the light source device comprise a plurality of interfaces; the testing device is a multi-channel testing device, all channels of the testing device correspond to all channels of the light source device, a chip used for calculating optical fiber attenuation is arranged in the testing device, a display screen used for displaying optical fiber attenuation is further arranged on the testing device, and the display screen isconnected with the chip. The optical fiber tester provided by the utility model has the beneficial effects that attenuation of optical fibers with different interfaces can be tested without replacingthe adapter, the test efficiency is high, and the measurement is more accurate.