The invention discloses a flexible circuit board convenient for efficient heat dissipation and mainly used in a high-power LED illumination array, belonging to the semiconductor illumination technical field. The flexible circuit board of an LED illumination array is characterized in that: the circuit board is provided with a flexible substrate, a connection circuit, an insulating film-covered layer, a heat-conducting rubber pad and an LED light source; the connection circuit is arranged on the surface of the flexible substrate; the surfaces of the flexible substrate and the connection circuit are covered with the insulating film-covered layer to form a circuit board module; the LED light source is packaged inside the circuit board module in an array mode; the bottom surface of the flexible substrate is adhered to the surface of the heat-conducting rubber pad. Therefore, the entire flexible circuit board module has certain elasticity and flexibility and can adapt to bending, twisting and crimp deformation of certain strength; moreover, the invention can also be arranged on non-flat surfaces not more than a certain curvature such as a cylindrical surface or a spherical surface. The invention has wider application scope, better heat dissipation performance, less production cost, convenient installation and substantially increased production efficiency.