There are several factors to consider when choosing a backpack: 1. Size and Capacity: Consider the number and size of items you need to carry. If you need a long trip, you need a larger capacity; if you only use it daily, the capacity can be smaller. 2. Material and durability: Choose high-quality materials and workmanship to ensure that the backpack can withstand weight and frequent use. 3. Comfort: Consider the comfort and adjustment of the straps, back panel, waist belt and other parts to ensure that wearing the backpack for a long time will not cause discomfort. 4. Special functions: If you need to carry out outdoor activities, you need to choose a backpack with functions such as waterproof and tear resistance. 5. Brand and price: Choose the backpack brand and price according to your personal consumption budget. In short, when choosing a backpack, you need to consider comprehensively according to your own needs and usage scenarios, and choose a product with high cost performance.