The High-Speed Laser Detector equipped with the avalanche photodiode detector, is a high-speed, high-bandwidth detector. It is very compact and user friendly. Users are able to carry out on-line detection of the laser from visible to near-infrared bands (400-1700 nm) by simply hand-holding the detector. The response time is 0.35ns. It can be used for fast optical signal related testing or measurement, including data communication, analog microwave and general high-speed photonics study, etc. When equipped with our fiber probe, the on-line measurement for narrow space, high temperature area and EMI area can be carried out.