Optical sensor as well as manufacturing method of optical sensor

The invention provides an optical sensor as well as a manufacturing method of the optical sensor. The optical sensor comprises a base plate, a control element and a photosensitive element, wherein the control element comprises a gate electrode, a gate insulating layer, an oxide semiconductor layer, a source electrode and a drain electrode; the photosensitive element comprises a lower electrode, an SRO thin film layer and a first transparent conductive layer; the lower electrode is coupled to the drain electrode through a first opening; the first transparent conductive layer is coupled to a second transparent conductive layer through a second opening; the process step of the SRO thin film layer is earlier than the process step of the oxide semiconductor layer. Compared with the prior art, in the process step, the SRO thin film layer is formed firstly and then the oxide semiconductor layer is formed. As hydrogen used when the SRO thin film is deposited does not affect the element characteristics of the oxide semiconductor layer, the threshold voltage of a control element is free of negative drift. In addition, the SRO thin film is protected by the gate insulating layer, and the subsequent low-temperature process procedure does not affect the characteristics of the SRO thin film.