Silver nanowire (AgNW) attracts great attention as a heat dissipation material due to its excellent thermal transfer property which exceeds most traditional heat sink materials. Heat accumulation has a vital risk for light-emitting diodes (LED) devices. In this work, a lateral heat spreader with enhanced thermal conductivity was reported as an additional escaping channel to improve thermal management of LED devices. A lateral heat spreader was prepared based on AgNW/polyvinylidene fluoride (PVDF) composite film which the AgNW was embedded in the PVDF matrix. The through-plane and in-plane thermal conductivity values of 25 vol% AgNW/PVDF composite film are 0.31 W (m K)⁻¹ and 127.6 W (m K)⁻¹ respectively, which far exceed that of pristine PVDF film, and are comparable to those of a commercial copper foil. The surface temperatures of AgNW/PVDF composite film during the transfer processes were captured by a thermal infrared imager and the contours of temperature distribution were simulated. Consequently, the simulated heat transfer is very consistent with actual situations. The data combined with computational simulation indicates that the heat transfers along the direction of AgNW and more Joule heat diffused efficiently along the lateral heat spreader.