Disclosed herein is a multipurpose water tank having an improved filtering function. The multipurpose water tank having an improved filtering function includes: an opening and closing cover configured to selectively open and close an opening portion formed in the top of the water tank； an accommodation space provided inside the water tank； a water introduction means provided on the upper portion of the water tank, and configured to filter agricultural water to be introduced into the water tank； and a pest control fluid introduction means provided on the side surface of the water tank, and configured to, when a pest control fluid is introduced into the water tank, filter out impurities included in the pest control fluid and then introduce the filtered pest control fluid into the water tank.
