A simple filtration and water purification device comprises a barrel (1), a water inlet (2), a cobblestone layer (3), a fine sand layer (4), a gauze layer (5), an activated carbon layer (6), a partition screen (7) and a water outlet (8), wherein the water inlet (2) is located in the middle of the upper part of the barrel (1), the cobblestone layer (3) is located below the water inlet (2), the fine sand layer (4) is connected with the cobblestone layer (3), the gauze layer (5) is connected with the fine sand layer (4), the activated carbon layer (6) is located below the gauze layer (5), the partition screen (7) is located below the activated carbon layer (6), and the water outlet (8) is located in the middle of the lower part of the barrel (1). The simple filtration and water purification device has the characteristics of being scientific, reasonable, simple in design, convenient to carry, rapid in filtration, safe, free of side effects and the like and can meet demands of people for outdoor activities.