It could affect the baryon number susceptibilities $\chi_n^B$ even at $\mu=0$, since $\chi_n^B$ depends on the derivative with respect to $\mu$. In this way, one might fix $\lambda_2,\lambda_4,\lambda_6$ by fitting the lattice results at $\mu=0$. However, in this work, we neglect the back-reaction. Therefore, we can not fix these three parameters in this way. In Fig.\[lambdas\], we show the effects of $\lambda$s on chiral condensate in wide parameter regions, $-50\leq \lambda_2 \leq50$, $-250\leq \lambda_4 \leq250$, $-\frac{-2000}{3}\leq \lambda_6 \leq\frac{2000}{3}$. From Fig.\[lambdas\], we could see that the parameters $\lambda$ is the coupling strength of chiral condensate with chemical potential and the sensitivity of $\lambda$ is presented. It is found that the effect of $\lambda_2$ is dominated, comparing with high order coupling term $\lambda_4$ and $\lambda_6$. The positive/negative sign in front of $\lambda$ will increase/decrease the transition temperature at the same chemical potential, which also means the location of CEP will appear at lower/higher chemical potential in $T - \mu$ plane. Without the coupling of chiral condensate with chemical potential, the deconfinement transition and chiral phase transition line will almost overlap. Thus, we choose these certain set of $\lambda$ to show the qualitative behavior of coupling strength in this model. Therefore, in the 