  In this paper, we explore the nonsingular cosmology within the framework of
the Effective Field Theory(EFT) of cosmological perturbations. Due to the
recently proved no-go theorem, any nonsingular cosmological models based on the
cubic Galileon suffer from pathologies. We show how the EFT could help us
clarify the origin of the no-go theorem, and offer us solutions to break the
no-go. Particularly, we point out that the gradient instability can be removed
by using some spatial derivative operators in EFT. Based on the EFT
description, we obtain a realistic healthy nonsingular cosmological model, and
show the perturbation spectrum can be consistent with the observations.
