I return to china every year to visit both 89 yrs parents. Can I apply 5 yrs multiple entry visa?

Sorry, the five-year multiple-entry type is now not available to Australian passport holders. You can apply for the one or two year multiple-entry type. Another option is to apply for a Q1 type if your parents are Chinese. If they are foreigners, you can apply for an S1 type. Both the Q1 type and S1 type allow you to stay about one or two year in China.