The invention discloses a liquid flow box for a liquid flow battery and a single battery thereof. The liquid flow box comprises a positive liquid flow box and a negative liquid flow box; two centro-symmetric positive shared flow channels and two centro-symmetric negative shared flow channels are respectively formed in four corners on the front side of the positive liquid flow box; centro-symmetric isolation membrane cover plate grooves on the left and the right are respectively formed in the reverse side of the positive liquid flow box and the front side of the negative liquid flow box; a first overturn hole, a secondary flow limiting channel, a splayed flow equalizing channel, a flow equalizing baffle table and a flow equalizing groove are sequentially formed in each of the isolation membrane cover plate grooves. The liquid flow box for the liquid flow battery, disclosed by the invention, has the advantages of being high in electric pile mounting success rate, free from internal and external leakage, convenient to mount, long in service life, convenient to maintain and the like, effectively protects an isolating membrane and can acquire the battery voltage and greatly promote the large-scale mass production and the application of the liquid flow battery.