Abstract: A device and a method for regulating and controlling an incident angle of a light beam in a laser interference lithography process are disclosed. The device comprises: a beam splitter prism between a first lens and a second lens, a first position detector, a first decoupling lens between the first position detector and the beam splitter prism, a feedback control system connected to the first position detector and a first universal reflecting mirror. The beam splitter prism reflects first incident light passing through the first universal reflecting mirror, the first decoupling lens enables a first reflected light enter into the first position detector, the first position detector measures the light beam position, the feedback control system outputs a control command according to the measurement result to regulate a mirror base of the first universal reflecting mirror, thereby regulating and controlling an incident angle of an exposure light beam.