The invention discloses a wave pressure based method for measuring wave parameters and tide level of a sea-spanning bridge construction sea area. The method comprises specific steps as follows: step 1, a test point is selected in the construction sea area, a plurality of wave pressure sensors are annularly arranged on the outer surface of a steel pipe pile located in the test point at intervals, and the wave pressure sensors are located in the position 2-4 m lower than a mean water level of the low tide level; step 2, a wave pressure time travel curve corresponding to each wave pressure sensor is generated according to wave pressure values collected by the wave pressure sensor; step 3, one wave pressure sensor with the maximum wave pressure value in a certain time period is selected as a reference wave pressure sensor, and the wave pressure time-travel curve of the reference wave pressure sensor is taken as a reference wave pressure time-travel curve; step 4, the wave parameters and the tide level are calculated according to the reference wave pressure time-travel curve. The structure is simple, and the method is used for comprehensively measuring the wave parameters and the tide level.