After studying the Shicha algorithm of parallax theory in Shoushi Calendar and Huihui Calendar, this paper points out that Shicha algorithm in Huihui Calendar is better than that of Shoushi Calendar about the completeness of variables, the choice of the sign of Shicha and the procession of Shicha algorithm, thus concluding that it can help us to evaluate objectively the solar eclipse theory of ancint China and Arabia.
阿拉伯传统视差算法包括东西差、南北差和时差。古代中国和阿拉伯视差算法中的时差具有相同的涵义，都指的是定朔时刻和日食视食甚时刻之间的时间差。在传统日食理论中，历法家设计日食时差的根本目的，是为了用时差修正定朔时刻，得到日食视食甚时刻。从这个意义上讲，一部历法中日食时差算法的优劣，可以在一定程度上反映这部历法的日食计算水平。
The application of parallax theory in solar eclipse arithmetic before the Xuan Ming Calendar is also discussed in the article.
同时，详细讨论了《宣明历》之前视差理论在日食食分算法中的应用。
Parallax plays an important role in the solar eclipse theory because it will affect the calculation and prediction of a solar eclipse, such as the time of the middle eclipse, the magnitude of the solar eclipse and the interval of a solar eclipse.
视差在日食理论中占有重要的地位，因为日食计算中的许多项目，如日食的食甚时刻、食分大小和食延时刻等的推求都会受到视差的影响。