River ice phenomena of water resources development and utilization are an important phenomenon to consider.Ice layer thickness detection is the main target to detect the ice condition.A fiber Bragg grating（ FBG）temperature sensor which is a connected type spiral structure is researched and fabricated.Based on the mechanism of temperature of ice and water change point

ice thickness can be obtained by detecting temperature of the water and ice and setting spacing between sensor arrays of vertical distribution.This FBG temperature sensor uses better thermal conductivity capillary copper for structural materials of spirochetes fabrication.Different thickness of the ice in the deglaciation process is detected

experimental results show that the maximum measurement error is 12 mm and the minimum measurement error is 0 mm.Spacing between each measuring point can be changed by adjusting slope of U-tube and angle of the plane of the straight tube.