Abstract: The sub-orbit tourism contract as a new contract has made it necessary that the related applicable principles should meet the requirements that have been put forward by such a contract. The characters of the sub-orbit tourism contract have offered the concrete requirements for choosing the way for applying laws. The principle of parties’ autonomy has obvious advantages to meet those requirements. It can’t be avoided to limit the principle of parties’ autonomy. However, the limitation should guarantee the function of the principle and should not expand to limit the object of law choice.