A sunlight tracking device comprising a solar panel holder, a mounting, a pitching angle tracking member, and a swing angle tracking member, wherein: the solar panel holder is coupled with the mounting through a three-dimensional joint, the three-dimensional joint includes a pitching angle rotation supporting shaft and a swing angle rotation supporting shaft arranged in a cross shape, the three-dimensional joint is hingedly coupled to the mounting through the pitching angle rotation supporting shaft, and the three-dimensional joint is hingedly coupled to the solar panel holder through the swing angle rotation supporting shaft; a rigid support is fixedly connected to the swing angle rotation supporting shaft of the three-dimensional joint, and the rigid support is only capable of rotating synchronously with a pitching angle of the solar panel holder; the swing angle tracking member at least comprises a transmission part which is capable of rotating the solar panel holder around the swing angle rotation supporting shaft of the three-dimensional joint, and a drive device fixed to the rigid support to drive the transmission part to act, characterized in that the pitching angle tracking member comprising: a rigid arc body which is capable of rotating the solar panel holder by means of the pitching angle rotation supporting shaft of the three-dimensional joint, wherein the rigid arc body has an end fixedly connected to the rigid support or the swing angle rotation supporting shaft, the rigid arc body has a hole-shaped, positioning structure; a fixing hole disposed in the mounting; and a positioning pin which is capable of being inserted in the fixing hole and the hole-shaped positioning structure of the rigid arc body, wherein the pitching angle of the solar panel holder can be manually adjusted and the rigid arc body is locked to the mounting by inserting the positioning pin in the fixing hole of the mounting and the hole-shaped positioning structure of the rigid arc body. the solar panel holder is coupled with the mounting through a three-dimensional joint, the three-dimensional joint includes a pitching angle rotation supporting shaft and a swing angle rotation supporting shaft arranged in a cross shape, the three-dimensional joint is hingedly coupled to the mounting through the pitching angle rotation supporting shaft, and the three-dimensional joint is hingedly coupled to the solar panel holder through the swing angle rotation supporting shaft; a rigid support is fixedly connected to the swing angle rotation supporting shaft of the three-dimensional joint, and the rigid support is only capable of rotating synchronously with a pitching angle of the solar panel holder; the swing angle tracking member at least comprises a transmission part which is capable of rotating the solar panel holder around the swing angle rotation supporting shaft of the three-dimensional joint, and a drive device fixed to the rigid support to drive the transmission part to act, characterized in that the pitching angle tracking member comprising: a rigid arc body which is capable of rotating the solar panel holder by means of the pitching angle rotation supporting shaft of the three-dimensional joint, wherein the rigid arc body has an end fixedly connected to the rigid support or the swing angle rotation supporting shaft, the rigid arc body has a hole-shaped, positioning structure; a fixing hole disposed in the mounting; and a positioning pin which is capable of being inserted in the fixing hole and the hole-shaped positioning structure of the rigid arc body, wherein the pitching angle of the solar panel holder can be manually adjusted and the rigid arc body is locked to the mounting by inserting the positioning pin in the fixing hole of the mounting and the hole-shaped positioning structure of the rigid arc body. a rigid arc body which is capable of rotating the solar panel holder by means of the pitching angle rotation supporting shaft of the three-dimensional joint, wherein the rigid arc body has an end fixedly connected to the rigid support or the swing angle rotation supporting shaft, the rigid arc body has a hole-shaped, positioning structure; a fixing hole disposed in the mounting; and a positioning pin which is capable of being inserted in the fixing hole and the hole-shaped positioning structure of the rigid arc body, wherein the pitching angle of the solar panel holder can be manually adjusted and the rigid arc body is locked to the mounting by inserting the positioning pin in the fixing hole of the mounting and the hole-shaped positioning structure of the rigid arc body.