The invention discloses a region prediction method for the sea wave field and wind speed field of cross-sea bridge construction, and the method comprises the steps: obtaining sample sea wave data forecast by a marine meteorology organization before the construction of a construction sea, and building a sample sea database; enabling the construction seat to be divided into a plurality of prediction monitoring regions, obtaining the actual measurement wave data of each prediction monitoring region, and building all prediction monitoring region databases; taking the sample sea database as an input learning sample, taking all the prediction monitoring region databases as output samples, and respectively building the corresponding relation between the actual data of each prediction monitoring region database in each day and the forecast data in the sample sea database at this day; extracting the wave height and wind speed forecast data of the sample sea in a future time period from the marine meteorology organization, taking the wave height and wind speed forecast data as the input data, and calculating the corresponding wave height and wind speed forecast data of each prediction monitoring region in the future time period. The method provides environment guide for the bridge construction.