不需要加介词。在this、that、next、last、every、yesterday、tomorrow等构成的时间状语前不加任何介词。
双语例句
1、I'll be in town next week if you want to meet.
如果你想见面的话，我下个星期在城里。
2、They are set to meet head-to-head in next week's final.
他们将在下个星期的决赛中正面交锋。
3、The new rules come into operation from next week.
新规定从下周起实施。
4、By this time next week we'll be in New York.
下星期的这个时候我们将在纽约。
5、I could come next week, or the week after.
我可能下周来，或者再下一周。