Disclosed is a PM2.5 cold/warm filter-window, comprising a water-screen filter apparatus (1) and an air conditioner (2). When an outdoor temperature is lower than or equal to 0°C, a controller (4) controls the air conditioner (2) to be in a working state of cooling, use hot water to generate a filter water-screen (30), prevent the filter water-screen (30) from solidification by cold wind, and absorb dust and PM2.5 in air by using the filter water-screen (30) formed of the hot water; when an outdoor temperature is higher than 0°C and lower than or equal to 25°C, the controller (4) controls a compressor (10) to stop running, and absorb dust and PM2.5 in air by directly using a filter water-screen (30); and when an outdoor temperature is higher than 25°C, the controller (4) controls the air conditioner(2) to be in a working state of heating, and absorb dust and PM2.5 in air by using a filter water-screen (30) formed of cooled water. In this way, fresh and cleaned air is provided indoors.