The utility model provides a water level change monitoring device, include flotation device, rack, gear, resistance wire dish and fixed platform, fixed platform sets up at the water level upside, and the resistance wire is twined in fixed platform one side on the resistance wire dish to gear and the concentric setting of resistance wire dish, and rack and gear engagement, rack lower extreme connect flotation device, the fixed pointer that electrically conducts of gear center, and electrically conductive pointer top and resistance wire contact, the resistance wire initiating terminal passes through the wire and constitutes closed -loop with the terminal series connection of power, ampere meter and electrically conductive pointer in proper order. The device drives flotation device through water level variation and reciprocates to the length that makes the resistance wire among the access circuit is different, thereby leads to the electric current different, can judge the height of water level according to the size of electric current, can realize the continuous monitor of water level, and is with low costs, easy operation.