The invention belongs to the offshore work platform personnel positioning field, and specifically relates to an offshore work platform personnel positioning method based on a wavelet decomposition low frequency coefficient; the method mainly comprises 6 steps: A, allowing a positioning label arranged on the oil zone work personnel to send a UWB signal, and allowing a positioning base station to receive the signal; B, allowing the positioning base station to carry out wavelet decomposition for the received UWB signal; C, extracting low frequency coefficients after wavelet decomposition to build an energy block; D, building a mapping relation between the threshold and the energy block kurtosis; E, carrying out actual range finding according to the received UWB signal; F, allowing a server to position the personnel according to the differences between the positioning label and different positioning base stations and a hyperbola algorithm. The method firstly applies the UWB signal, wavelet decomposition and wavelet decomposition low frequency coefficient constructed energy block to the offshore work platform personnel positioning, thus improving the personnel range finding positioning precision under offshore oil zone specific working conditions like multipath, non-LOS and multi-metal environments.