To provide an assembly fixture capable of easily assembling two vane pumps in a state of being precisely aligned.

Bolt holes h1, h5 of a pair of first side plates 21L, 21R of two vane pumps PL, PR, bolt holes h2, h4 of a pair of cam rings 22L, 22R and bolt hole h3 of a second side plate 23 are fitted to the locate pin 63 provided on a first fixture body 61, and a second fixture body 64 is inserted from above. After both of the first side plates 21L, 21R are aligned by the engaging of positioning tapered surfaces 62a, 69a, the engaging of positioning tapered surfaces 61a, 21a and the engaging of positioning tapered surfaces 65a, 21b, the bolts 24 are inserted into the bolt holes h1 to h5 in which the locate pin 63 is not inserted, and fastened. Finally, the bolt 24 is inserted into the bolt holes h1 to h5 from which the locate pin 63 is pulled out, and fastened.