The invention discloses an adjustable strip-flat-plate heat collecting device which comprises a plurality of heat absorbing pipes, strip-flat-plate heat collectors, supporting elbows, a connecting rod and two main pipes, wherein the two main pipes and the heat absorbing pipes are horizontally placed and perpendicular to each other; the supporting elbows are connected with both ends of the heat absorbing pipes and fixed at the upper parts of the main pipes; each heat absorbing pipe is sleeved with one corresponding strip-flat-plate heat collector, and the strip-flat-plate heat collector can rotate around the heat absorbing pipe; and all the heat absorbing pipes are connected through one connecting rod. By adoption of the adjustable strip-flat-plate heat collecting device, not only can the heat collecting efficiency of heat collecting units be guaranteed, but also the size and the weight of the heat collecting units can be reduced to the greatest extent; the heat collecting units need not be supported; the adjustable strip-flat-plate heat collecting device is simple in structure, low in cost, and easy to mount and maintain; meanwhile, the angle adjustment operation can be performed; the influence on the appearance of a building is avoided; the stability and the reliability are high; and the adjustable strip-flat-plate heat collecting device has the promotion potential.