First find the number of the target area according to the picture below. Eastern China belongs to UTM Zone 50N
DMAP: UTM Grid Zones of the World
Find the EPSG implementation standard for UTM 50N Coordinate reference systems for "UTM zone 50N"
WGS 84 / UTM zone 50N
EPSG:32650
>>> from pyproj import Proj,transform
>>> WGS84 = Proj(init='EPSG:4326')
>>> p = Proj(init="EPSG:32650")
>>> x,y = 526434.351935, 3522210.609046
>>> transform(p, WGS84, x, y)
(117.27936202563953, 31.835267862875163