Abstract: For Power Line Communication channels multipath delay effects and impulse noise,the system of LDPCOFDM based on low-voltage power line is built.The Low Density Parity Check Codes decoding algorithm is studied based on the system.According to the min-sum BP algorithm,a coefficient is designed to modify layered sum-product algorithm,so the layered min-sum BP algorithm based coefficient is proposed.The algorithm is convenient to implenment for its low decoding complexity and fast speed of iterative.The simulation shows that the algorithm not only achieve a better error performance under the systerm of LDPC-OFDM,but also improve the transmission efficiency.