Please don't even think of bringing these items. At the least they'll be confiscated and/or you risk a fine. At worst you may jeopardize your visa.
As a general guideline, clothing and kitchenware can be imported into China duty free.
Personal effects, furniture, electrical and electronic items, stereo equipment, office equipment, wine, liquor, alcoholic drinks, cigarettes and tobacco, motor vehicles and motorcycles, are subject to import tax and duty. In general, the import tax and duty charged on furniture and personal effects is approximately 10% to 30% based on Customs assessed value. If more than one of each type of the major appliances is included in a shipment (i.e. refrigerators or televisions etc.), Customs may consider the shipment containing commercial goods thus making clearance very difficult.
Things that you should leave behind as they attract a LOT of duty (as of last year) and you can easily replace them here
Also leave behind any Chinese antiques you may have, since you can probably import them, but may have a problem getting them back out when you leave.
1) stock up on paracetamol, ibuprofen and cold and flu medication
2) large jar of marmite
3) big block of cheddar cheese and a big blog of Parmesan. Cheese is expensive
4) herbal teas like mint and ginger.
5) you can find herbs and spices at places like Sanyuanli and there are WeChat groups but stock up on all the essentials you might need for making curries. Hard to find things like mustard seeds, coriander seeds, asafoetida etc.
6) suntan lotion - Chinese suntan lotion often has a whitening agent in it.
7) don't bring chocolate - New Zealand Whittaker's chocolate is in plentiful supply and in all the supermarkets like Jenny Lou's, April Gourmet etc.
8) A few packs of British bacon to tide you over - various butchers claim to make British bacon but no-one gets it quite right.
9) DON"T bring your wellies. You will never wear them!