The invention discloses a water quality monitoring system including a bubble removing device, a sensor and a sampling pool; the bubble removing device is used for removing bubbles in a to-be-measured water sample and is provided with a water inlet part, a main body part and a water outlet part which are connected successively; the water inlet part is used for inputting the water sample; the main body part is used for removing the bubbles in the water sample; the water outlet part is used for outputting the water sample to the sampling pool; the sensor is arranged in the sampling pool and is used for monitoring the water sample; the sampling pool is provided with a water discharge port used for discharging the water sample. With use of the system, the water sample which flows uniformly and has the bubbles removed can be obtained, a water body making contact with a measurement surface of the sensor can be replaced in real time, and water body monitoring is facilitated to be carried out efficiently, continuously and accurately.