The invention discloses a solar collector installed with horizontally inserted, densely arranged and jacking metal section tube composite evacuated solar collector tubes, which comprises a water tank, metal section tube composite evacuated solar collector tubes, a fixed support and jacking tailstocks. The water tank is longitudinally installed and fixed at one end of the support, coaxial holes for inserting the metal section tube composite evacuated solar collector tubes are arranged at the same sides of the outer barrel, an insulating layer and a liner of the water tank, or the water tank is longitudinally installed and fixed in the middle of the support, and coaxial holes for inserting the metal section tube composite evacuated solar collector tubes are arranged at the two sides of the outer barrel, the insulating layer and the liner of the water tank; and the single-pass tube joints of the metal section tube composite evacuated solar collector tubes are inserted into the sealing rings of the pores of the liner, the tail ends of the evacuated solar collector tubes are tightly jacked by jacking tailstocks, and thereby the horizontally inserted and densely arranged installation of the evacuated solar collector tubes is realized. The invention improves the stability and durability of a solar water heater system, realizes the perfect combination with buildings, and adds functions of heat insulation and building materials to the solar collector under the premise of maintaining the heat collecting function thereof.