The International Earth Rotation and Reference Systems Service (IERS) released the updated International Terrestrial Reference Frame ITRF2020 in April 2022 (the International Terrestrial Reference Frame 2020). The accuracy of ITRF2020 is better than that of ITRF2014 because of the adoption of a longer time series, better processing models, and more optimized processing strategies. Compared with ITRF2014, ITRF2020 has significant improvements in the strategies for implementation of origin and scale parameters, and for the first time it explicitly provides the origin, scale, and orientation of seasonal signals; that is,
the strategy of segmented alignment is adopted to improve the origin and scale parameter realization;
the origin, scale, and orientation realizations of seasonal signals in the Center of Mass (CM) and Center of Figure (CF) frames, as well as the harmonic parameter models in the CM and CF frames, are given. In addition, there have been significant technological advances in data processing for each of the independent techniques involved in the construction of ITRF2020. In this paper, we first introduce in detail the progress of data processing within the four space geodetic technologies and the technical progress of the inter-technology combinations, then briefly analyze the ITRF2020 implementation, and finally provide a preliminary analysis and discussion of its shortcomings.