The utility model discloses an anti-jitter circuit for a water temperature protection signal of a seedling raising plate. The anti-jitter circuit comprises two functional modules: an over-temperature signal detection circuit composed of a chip IC1D and circuits around the chip IC1D; the signal anti-jitter circuit is composed of a chip IC2D and circuits around the chip IC2D; the IC1D is an LM2901 comparator chip, the IC2D is an RS trigger chip, and the Q4 end of the trigger chip is the output end of the whole circuit; the circuit provided by the utility model can immediately latch and maintain an over-temperature protection signal after detecting the over-temperature protection signal, and can detect an over-temperature pulse even if the over-temperature protection signal disappears after appearing, thereby avoiding the technical problem that the temperature protection circuit continuously jumps at a critical water temperature, and improving the reliability of the temperature protection circuit. An unattended seedling raising environment is powerfully supported, and the method has a better economic purpose.