Let μ(n) be the M"obius function, e(z)=exp(2πiz), x real and
2≤y≤x. This paper proves two sequences (μ(n)) and $(e(n^k
\alpha))arestronglyorthogonalinshortintervals.Thatis,ifk \geq 3beingfixedandy\geq x^{1-1/4+\varepsilon},thenforanyA>0$, we have x<n≤x+y∑μ(n)e(nkα)≪y(logy)−A
uniformly for α∈R.