A method for light intensity detection, comprising: determining (101, 201, 301) whether light intensity detection needs to be performed; detecting (102, 202, 302) whether there is a finger touch in an optical detection region of an optical fingerprint sensor if light intensity detection needs to be performed, wherein the optical detection region is located in at least a part of a display region of a display and the optical fingerprint sensor is integrally arranged with the display to form an under-display structure; enabling (103, 204, 304) a light intensity detection function of the optical fingerprint sensor if no finger touch is detected; collecting (103, 204, 304) light intensity data by using the optical fingerprint sensor; and processing (104, 206, 3061) the collected light intensity data, and calculating a value of current ambient light intensity according to the light intensity data; wherein the detecting whether there is a finger touch in the optical detection region is done using a touch sensor; wherein the optical detection region of the optical fingerprint sensor includes a fingerprint detection subregion and a light intensity detection subregion, wherein the optical fingerprint sensor performs the fingerprint detection function by using sensing units in the fingerprint detection subregion, and performs the light intensity detection function by using at least one sensing unit in the light intensity detection subregion; wherein the light intensity detection subregion is in the fingerprint detection subregion; and at least some sensing units in the fingerprint detection subregion are further used as sensing units in the light intensity detection subregion. determining (101, 201, 301) whether light intensity detection needs to be performed; detecting (102, 202, 302) whether there is a finger touch in an optical detection region of an optical fingerprint sensor if light intensity detection needs to be performed, wherein the optical detection region is located in at least a part of a display region of a display and the optical fingerprint sensor is integrally arranged with the display to form an under-display structure; enabling (103, 204, 304) a light intensity detection function of the optical fingerprint sensor if no finger touch is detected; collecting (103, 204, 304) light intensity data by using the optical fingerprint sensor; and processing (104, 206, 3061) the collected light intensity data, and calculating a value of current ambient light intensity according to the light intensity data; wherein the detecting whether there is a finger touch in the optical detection region is done using a touch sensor; wherein the optical detection region of the optical fingerprint sensor includes a fingerprint detection subregion and a light intensity detection subregion, wherein the optical fingerprint sensor performs the fingerprint detection function by using sensing units in the fingerprint detection subregion, and performs the light intensity detection function by using at least one sensing unit in the light intensity detection subregion; wherein the light intensity detection subregion is in the fingerprint detection subregion; and at least some sensing units in the fingerprint detection subregion are further used as sensing units in the light intensity detection subregion.