Aiming at the problem of poor signal detection performance and short communication distance of traditional direct-currnt biased orthogonal frequency division multiplexing(DCO-OFDM) underwater light-emitting diode(LED) visible light communi-cation system, a signal detection method of underwater LED visible light communication based on support vector machine(SVM) is proposed. Firstly, grid search and cross validation are performed on the signal data to obtain the optimal SVM model, then the received signal is judged by the model. The simulation results show that the system performance based on SVM is equivalent to that based on direct decision least mean square(DD-LMS) at the same communication distance and low signal to noise ratio(SNR), when the SNR is high, the former is better than the latter. Under the same bit error rate, when the communication distance is less than 3 m, the communication distance of the system based on SVM detection is slightly longer than that of DD-LMS detection.