To be a PHD or not

Two days ago I thought this year will be very important for me and it's time to make a change, then something turning point happened, my tutor asked me whether to want to be a full scholarship PHD. CS is best in Beihang and Beihang is top in China. Privately, I think I am not suitable to make research, about basic mathematics. And I am also concerned that it will take at least five years to finish a phd. So it is hard to decide and i need one more days to think about it.