Steroid compound, and use thereof and preparation method therefor

A compound of Formula (I):

• or a pharmaceutically acceptable salt thereof,
• wherein:
• R1 is hydrogen, substituted or unsubstituted C1-6 alkyl, substituted or unsubstituted C1-6 alkoxy, substituted or unsubstituted C2-6 alkenyl, substituted or unsubstituted C2-6 alkynyl, or substituted or unsubstituted C3-6 carbocyclyl,
• R2 is hydrogen, halogen, substituted or unsubstituted C1-6 alkyl, substituted or unsubstituted C1-6 alkoxy, substituted or unsubstituted C2-6 alkenyl, substituted or unsubstituted C2-6 alkynyl, substituted or unsubstituted C3-6 carbocyclyl,
• R3 is hydrogen, unsubstituted C1-6 alkyl or —CH2ORa, wherein Ra is hydrogen, substituted or unsubstituted C1-6 alkyl, substituted or unsubstituted C1-6 alkoxy, substituted or unsubstituted C2-6 alkenyl, substituted or unsubstituted C2-6 alkynyl, substituted or unsubstituted C3-6 carbocyclyl;
• L is —C(Rb)(Rb)—, each Rb is independently hydrogen or C1-C6 alkyl, n is an integer of 0 to 3;
• R4 is halogen or substituted or unsubstituted heteroaryl or heterocyclyl.