The utility model provides a connection structure of a collection tube of a solar collector, the connection structure of the collection tube of the solar collector can effectively prevent a connection piece of the collection tube from moving under the influence of external force. The solar collector is provided with a frame, the frame is provided with a planar plate part (2), a first through hole (2a) is arranged on the plate part, the connection piece (1) of the collection tube is arranged in the first through hole (2a), and the connection piece (1) of the collection tube is used to connect a connection tube of the collector outside the collector and the collection tube inside the collector. A convex edge (5) is formed on the outer circumference of the connection piece (1) of the collection tube, more than two through holes (5a) are arranged on the convex edge (5) along the circumferential direction, second through holes (2b) corresponding with the through holes (5a) are arranged on the planar plate part (2), and firmly fixing pieces fixing the connection piece (1) of the collection tube and the planar plate part (2) of the frame into a whole are arranged in the through holes (5a) and the second through holes (2b).