The invention discloses an LED modular street lamp holder with an adjustable irradiating angle, which comprises a lamp holder end cover, LED light source modular components, a side frame, a supportingframe, a lamp holder upper cover, a lamppost pressing board, a connecting rod, a rotating shaft, an LED light source driver, a lamp holder lower cover, an installation pressing board, a lower connecting frame and an upper connecting frame, wherein the lamp holder lower cover is assembled and fixed with the lamp holder upper cover after the LED light source driver, the supporting frame, the rotating shaft and the connecting rod are arranged on the lamp holder upper cover. The LED light source modular components are arranged on the side frame and the upper connecting frame and locked and fixedwith the supporting frame; the lower connecting frame is arranged on the upper connecting frame so as to lock and fix the lamp holder end cover on the supporting frame, the side frame and the upper connecting frame. The LED modular street lamp holder has the advantages of high light efficiency, stability, energy conservation, environmental protection and the like, has convenient and fast assemblyand a good radiating effect, and can meet the requirements of LED roadway lighting at different powers by increasing or decreasing the number of the LED light source modular components.