Abstract: This paper analyzed the effect of parameters on estimation of onset times for teleseismic P waves by AR-AIC （auto-regression Akaike information criterion）, HOS （higher order statistics） and CUSUM （cumulative sums） methods. The parameters of each method were optimized in the way of grid searching by taking 450 teleseismic P phases as sample set and the manual picked arrival times as reference. And then 100 teleseismic P phases were reselected with SNR between 2 and 20, and the onset times were estimated by the three methods with optimized parameters, so as to evaluate the accuracy of estimation for low-SNR teleseismic P phases. The results show that the accuracy of estimated phase arrival times by the AR-AIC and CUSUM methods is better than by the HOS method, the calculation speed by the CUSUM method is the fastest, and the HOS method is better applied to high-SNR and sharp onset signals.