"For my case, I ask my vendor to change its invoice date to the last day of last year,"
Due Date controls nothing except if the bill is Paid on time or not.
"so I record this as last year expenses ^^,and the date of paper invoice is same as the system record."
Bill date, not Due Date, creates the accrual entry for what is the details on the bill.
This is not an accrual, it is a normal purchase. Some business types would have reported the amount of the Bill as Work in Progress at the 2015 yearend. Record the Vendor Bill like any other with a date in the current fiscal year.