This English idiom is easy to understand. It is difficult for you to scratch your own back. If one scratches your back, you are expected to scratch his back. The meaning of this idiom is that "if you help me I help you". However, you should try to avoid using this line on a business associate, such as an employee of a client or a supplier, who you do not know well. If it is misunderstood or twisted by the listener, you may get into trouble if he alleges that you are offering a  bribe or an advantage to him. So be careful in such situation.

To put this line into good use I will give an example here as follows: You scratch my back I scratch yours. You  join my blog and I join yours".

这一谚语直译意思是“你给我搔背我会 给你搔"或"你帮我我帮你",但这句话尽量不要在陌生人面前说尤其是对方是客户或供应商, 他可指你贿赂或向他提供便利,这等同我们说"你给我好处,我不会亏待你“ “你关照我我会关照你“, 我举的例句是“你加我为博友我会加你为博友“。