The invention relates to seawater desalination equipment namely spline flange zinc alloy seawater desalination treatment equipment. An indoor hand-operated entertainment device drives a planetary speed-increasing gearbox to rotate at a high speed and penetrate through a transmission pipe isolation hole of a separation wall from inside to outside by virtue of a zinc alloy spline coupling to drive a centrifugal lift pump to obtain seawater from a submarine water filter by virtue of a lifting water inlet pipe; the obtained seawater penetrates through a water pipe isolation hole of the separation wall from outside to inside by virtue of a lifting water outlet pipe to sequentially flow into a micro electrolytic tank treatment device and a dust-slag precipitation and filtration device and then enter a clean seawater standby tank for later use; a micro plunger pump is built in each of pairwise-arranged pedal entertainment devices; a high-pressure pump water inlet pipe of each micro plunger pump is connected with the clean seawater standby tank; a high-pressure pump water outlet pipe of each micro plunger pump is connected with an osmotic membrane inlet of a reverse osmosis membrane component; fresh water permeating out of an osmotic membrane outlet flows through an activated carbon adsorption tank, and is subjected to treatment; then standard fresh water which meets the domestic drinking standard is finally supplied to a fresh water storage tank for domestic drinking of people on an isolated island.