In order to meet the unmet needs of rare disease patients in China, importing orphan drugs is an important way. The objectives of this study were to investigate the marketing trend of orphan drugs approved by the US Food and Drug Administration (FDA) and imported by China, to examine the orphan drug lag between China and the United States. This study analyzes the orphan drugs approved by FDA and imported by China from January 2010 to December 2021. The approval lag for orphan drugs between China and the US was calculated and analyzed by approval time. Factors potentially affecting the approval lag, such as target disease, ATC classification, formulation, corporation name, drug type, and whether the indications belong to the first batch of rare diseases catalogue were investigated. The number of FDA-approved orphan drugs imported by China is increasing year by year, and the approval lag of these drugs is gradually decreasing, especially in the classification of Non-L, Injections, Non-United States, and biological product. Compared with 2010-2015, the approval lag of total drugs in the study was significantly improved in 2016-2021 (1977days) compared with 2010-2015 (3928days). China's groundbreaking regulatory reforms of drugs since 2015 had made significant progress in reducing orphan drug lags, but there is still considerable room for progress. We should more actively promote the approval of rare disease drugs in China, establish a better approval mechanism, and enable Chinese patients with rare diseases to receive drug treatment in a timely manner.