The estimation methodology for the nonparametric mixed effects model is proposed. For this, we use the Bsplines methods to estimate the function, and employ the penalized least square method to obtain the estimator of the random effects. Further, we construct the normal likelihood function to estimate the variance components. And we also prove the consistency of variance components and the asymptotic normality of the link function.A simulation study is carried out to show the estimation effect of our proposed methodology.It shows our proposed methodology performs well.Our algorithm is stable numerically.