An optical sensor module is provided. The optical sensor module includes a light source, a first lens and a sensor device. The light source is arranged for generating a light signal. The first lens has a first optical center axis. The sensor device is disposed in correspondence with one side of the first lens. The sensor device includes a light sensitive area, and a center of the light sensitive area deviates from the first optical center axis. The sensor device is arranged for receiving a reflected signal reflected from an object in response to the light signal, and accordingly generating a sensing result.