Do China passport holders need a visa to visit AD?

Yes - a Chinese ordinary passport holder needs a visa. Andorra has no airport and is reachable only through France or Spain, so you must hold a (preferably multiple-entry) Schengen short-stay visa. Andorra is a microstate with no airport or seaport; every visitor must transit through France or Spain, both of which are in the Schengen area. Andorra itself issues no tourist visa and has no embassy network for short visits, so entry is governed de facto by Schengen rules. Chinese ordinary passport holders are not visa-exempt for Schengen and must obtain a Schengen Type C short-stay visa from the consulate of the main destination (France or Spain). Because Andorra sits just outside the Schengen zone, leaving Andorra means re-entering Schengen, so a MULTIPLE-ENTRY Schengen visa is strongly recommended to avoid being refused re-entry. The 90-days-in-any-180-days limit covers the entire Schengen area plus time in Andorra. The visa fee is EUR 90 for adults, processing is around 15 calendar days, and travel medical insurance of at least EUR 30,000 is mandatory. ETIAS does NOT apply to Chinese nationals because it is only for visa-exempt travelers; visa holders are outside its scope.