The output power of a tidal energy converter is an important indicator for measuring its economic performance. The output power characteristics of the tidal energy converter are crucial for calculating the annual energy production of the tidal energy converter. It is also very important for evaluating the overall economic performance of tidal energy converters. In view of this, this article addresses the scientific problem that the tidal current velocity data obtained during the field testing period of tidal energy converters may not cover the annual variation range of tidal current velocity in the field testing sea area. Uncertainty analysis, theoretical derivation, and model verification methods have been used to analyze the distribution patterns of tidal current velocity data and output power data of the tidal energy converter. The output power prediction method has been studied, a mathematical model for the distribution frequency of current velocity data and electric power data has been established, and the field testing data of the power performance characteristics of tidal energy converters have been applied for verification. The results show that the tidal current velocity data obtained during the field testing do not strictly follow the normal distribution law, and the data with current velocities exceeding 2.0 m/s accounts for about 7.0% of the statistical dataset. However, the output power data of the tested tidal energy converter show an exponential function distribution law, and the fitted curve determination coefficient is 0.99; When the tidal current velocity bin is 2.3 m/s, the difference between the predicted output power by the model and the average power calculated by the bin method reaches its maximum value, which is about 3.5% of the average output power that calculated by the method of bin. The maximum uncertainty of the established two datasets is approximately 2.9% of their output power. The uncertainty propagation coefficient of tidal current velocity generally shows a gradually increasing trend with the increase of tidal current velocity. The research results are expected to provide a reference for the overall economic performance evaluation of tidal energy converters.