Is the elevation of Beijing coordinate system the same as that of Xi 'an coordinate system?

In 1987, China defined the mean sea level of the Yellow Sea measured by Qingdao tide gauge station at1952+0 ~1979+12+31as the national elevation starting surface. It is estimated that the elevation of the origin of Qingdao Guanxiangshan national leveling is 72.260m ... The height system established according to the elevation datum is called 1985 national elevation datum. The elevation of each point in China refers to the height calculated from the average sea level of the Yellow Sea.

Beijing coordinate system and Xi 'an coordinate system have the same elevation. Extracted from the same height data.