Low-temperature ethylene vertical multi-stage pump

The invention discloses a low-temperature ethylene vertical multi-stage pump, and relates to a vertical multi-stage pump, the low-temperature ethylene vertical multi-stage pump comprises a vertical pump body, one end of the vertical pump body is fixedly inserted with a liquid conveying pipe; a positioning rack is engaged with a positioning gear, the positioning gear is engaged with a clamping rack, and the clamping rack abuts against the inner side wall of a second positioning box, so that low-temperature ethylene in a tank body generates pulling force on a liquid conveying pipe and a first positioning box, and the clamping rack pushes the second positioning box in the opposite direction; due to the fact that the second positioning box is fixedly connected with the connecting pipe, the problem of leakage caused by untight sealing due to looseness between the second positioning box and the first positioning box can be avoided, and when the second positioning box and the first positioning box are detached, an e