Hydroxypropyl chitosan passivated Cs3Bi2Cl9 quantum dots (HPCS-PQDs) were prepared using ligand assisted reprecipitation method. The morphology and optical properties of HPCS-PQDs were characterized by TEM, XRD, PL, and UV-Vis. And it was loaded onto cellulose filter paper to obtain an HPCS-PQDs sensor, and the selectivity, anti-interference ability, and sensitivity of the sensor for detecting UO22+ were studied. The results showed that HPCS-PQDs were spherical with an average particle size of 3.21 nm, emitting blue fluorescence. The emission peak was located at 440 nm, and the half maximum width of the emission peak was about 50 nm. When the UO22+ concentration is between 0 and 100 μmol/L, as the concentration of UO22+ increases, the blue fluorescence of the sensor gradually decreases. The quenching efficiency (F0-F)/F0 of HPCS-PQDs sensor has a good linear relationship with UO22+ concentration, with a detection limit of 0.23 nmol/L. In addition, HPCS-PQDs have good selectivity and anti-interference ability, which can be used for rapid detection in actual water samples. The spiked recovery rate of actual samples is 90.0%~99.8%, and the relative standard deviation is less than 5%. This method has the advantages of simplicity, speed, and efficiency, and can achieve visual detection of UO22+ in environmental water samples.