The stroke order of "忄" should be left dot, right dot, and vertical.
1. "Modern Chinese Common Character Stroke Order Standards"
The first edition of "Modern Chinese Common Character Stroke Order Standards" in August 1997 explains the stroke order of "忄" as follows: Left Click, right click, vertical. "Modern Chinese Common Character Stroke Order Standards" is formed on the basis of the "Modern Chinese Common Character List", compiled by the Standardization Working Committee of the National Language and Character Working Committee, and published by the National Language and Character Working Committee and the People's Government of the People's Republic of China and the National News Jointly issued by the Ministry of Education and the Ministry of Education, it is authoritative and should be conscientiously implemented in Chinese character teaching.
2. Historical writing method:
The stroke order of "忄" has been different for a long time: "vertical, left point, right point" "left point, Right click, vertical", etc. The "Modern Chinese Common Character Stroke Order Standards" regulates them in line with the principle that stroke order writing should take into account convenience, systematicity and other aspects (see Gauguinson's "Modern Chinese Character Standardization Issues", The Commercial Press, December 2002, 1st Edition 358 ~ Page 359), the standard stroke order of "忄" is "left point, right point, vertical", which can reflect the connection between left point and right point. It is convenient and quick to write from top to bottom, and at the same time, it takes care of the "vertical" as a whole. "Exposed vertically" is the characteristic of the main writer closing his pen when writing. Calligraphers of the past dynasties used the stroke order of "left dot, right dot, vertical" in many cursive and running scripts with the word "忄".