Solid rocket engine final assembly tool

The solid rocket engine final assembly tool comprises at least two holding rings, each holding ring at least comprises an arc-shaped body, an upper connecting piece is arranged at the upper end of each arc-shaped body, a lower connecting piece is arranged at the lower end of each arc-shaped body, and at least two supporting lugs are arranged at the front end of each arc-shaped body; during operation, the two embracing rings are fixed to the front end or the tail end of the charging combustion chamber, the upper connecting piece of one embracing ring is connected with the lower connecting piece of the other embracing ring, and the lower connecting piece of one embracing ring is connected with the upper connecting piece of the other embracing ring; the two embracing rings fasten the spray pipe or the front end socket through the supporting lugs, after the spray pipe or the front end socket is pressed to the needed position, a check ring and a key block or a wedge ring are installed, and the check ring, the key