Color developing polyethylene film, packaging bag and color developing reagent strip

The invention discloses a color developing polyethylene film, a packaging bag and a color developing reagent strip, and the color developing polyethylene film comprises an outer layer, a middle layer and an inner layer; the outer layer consists of low-density polyethylene resin and linear low-density polyethylene resin; the middle layer comprises low-density polyethylene resin and/or linear low-density polyethylene resin; the middle layer further comprises an acid-base indicator; the mass ratio of the acid-base indicator in the middle layer is 1%-3%; the inner layer is formed by combining at least two of low-density polyethylene, linear low-density polyethylene and metallocene linear low-density polyethylene. The acid-base indicator is arranged in the middle layer, whether the pH value of the packaging content changes or not is reflected through color changes of the color developing polyethylene film, and therefore whether the packaging content goes bad or not is judged more accurately. 本发明公开了一种显色聚乙烯薄膜、包装袋及显色