The present invention belongs to the technical field of medicine, relating in particular to: a fused ring compound as represented by Formula (I) for use as a mineralocorticoid receptor antagonist, a pharmaceutically acceptable salt thereof, and an isomer thereof； a preparation method for these compounds； a pharmaceutical preparation containing these compounds； and an application of these compounds, the pharmaceutically acceptable salt thereof, or the isomers thereof in the preparation of medicants for the treatment and/or prevention of kidney injury, cardiovascular diseases such as hypertension, and/or endocrine disease. The definitions of X, Y1, Y2, Y3, R1, R2a, R2b, R3a, R3b, R4, Cy and n are as presented in the description.
