Abstract: An easily collapsible and portable water filtering device mainly includes an outer barrel, an inner barrel, a filter unit, a water reserving space and a water dispensing valve. The outer barrel has a rigid first upper frame section and a soft watertight outer bag. The inner barrel has a rigid second upper frame section and a soft watertight inner bag. The filter unit is fixed on a fixing bottom edge of the bottom end of the inner bag. The filter unit contains a replaceable filtering member. The water reserving space can store certain filtered water. So, this invention is easily collapsible, suitable to be used in the wild filed, and can serve as a mini-type water reserving kettle temporarily.