You don’t need to spend lots of money on commercial cleaners in order to clean your upholstery. Make your own cleaner with natural ingredients instead. Mix 1 part water with 1 part dishwashing liquid in a bucket or jug. Mix together and put into a spray bottle.  Spray the mixture onto the upholstery, holding the bottle approximately 6-8 inches away. Rub the upholstery gently with a soft-bristled brush. Rinse the area with warm water by using a clean rag. Rinse out the rag frequently. Work on one seat or area at a time. Rinse each area thoroughly before moving onto the next area. Use a microfiber cloth to dry the area. To make another natural, non-caustic cleaner, grate a bar of soap (such as Ivory) until you have 6 tablespoons worth. Add this and 2 tablespoons of borax to a bucket. Slowly add 2 cups of boiling water. You can also add 10 drops of lavender essential oil for fragrance if you want. Allow this to cool and then whip it with a whisk until it is foamy.  Brush the foam onto your upholstery with a soft-bristled brush. Rinse the area with warm water by using a clean rag. Rinse out the rag frequently. Work on one seat or area at a time. Rinse each area thoroughly before moving onto the next area. These cleaners are readily available at home supply stores and are not very expensive. They do, however, tend to use harsher chemicals. Follow the instructions on the product’s label for proper usage. Apply the cleaner to your upholstery and use a brush to work it into the upholstery. Rinse with water thoroughly. Steam cleaners are available to rent at many grocery stores. These will deep clean upholstery and carpet by running hot water over the area that you’re cleaning and then sucking it back up immediately. This will extract the water from the upholstery along with dirt. Steam cleaners can cost $35-$40 for a 24-hour rental period.  Follow the instructions to operate the steam cleaner correctly. You can purchase a commercial carpet/upholstery cleaner to use in this machine, or you can make a natural solution...

TL;DR in Chinese:
自制多功能内饰清洁剂。 用肥皂、硼砂和热水自制混合清洁剂。 购买内饰清洁剂。 租一台蒸汽吸尘器。 用牙刷清洁内饰接缝。 清洁脚垫。 使用粘尘辊。 使用超细纤维布。