Graphene sensor and its manufacturing method and a touch display device

The present invention provides a method of making a graphene touch sensor, comprising: forming a graphene layer on a substrate; forming a metal layer on the graphene layer; photoresist is coated on the metal layer; of gray order mask exposing the photoresist, a photoresist is completely removed after development area, part of the photoresist and the photoresist completely-retained region reserved area; removing the photoresist is completely removed and the metal layer region graphene layer; removing the metal layer remained in the photoresist region; graphene layer coated with a protective film of the photoresist portion reserved areas; stripping of the remaining photoresist. The present invention further provides use of the above-described method for manufacturing a graphene sensor obtained graphene and includes a touch sensor of the display device. The present invention avoids the alkaline developer and lithographic process alkaline stripping solution in contact with the graphene film causes problems of deterioration of electric conductivity, improving the yield, reducing the cost.