A suspension particle sensing apparatus includes a first flow channel, a suspension particle concentration sensor and a suspension particle filtering assembly. The first flow channel has a first entrance and a first exit. The suspension particle concentration sensor is disposed in the first flow channel, and is located between the first entrance and the first exit. The suspension particle filtering assembly is disposed at the first entrance, and includes a casing and a suspension particle filtering structure. The casing has a first opening and a second opening. The first opening is communicated with the first entrance of the first flow channel. The suspension particle filtering structure covers the second opening.