Photosensitive polyimide resin composition as well as preparation method and application thereof

The invention discloses a photosensitive polyimide resin composition as well as a preparation method and application thereof. The composition comprises the following components in parts by mass: 100 parts of photosensitive polyamic acid ester resin, a low-temperature curing accelerator and alkali-soluble polyfunctional group photosensitive epoxy resin, 3-25 parts of a photopolymerization initiator, 10-30 parts of a photopolymerizable monomer, 15-45 parts of a thermocuring component and 10-80 parts of inorganic filler, the mass of the photosensitive polyamic acid ester resin is 4.5%-60% of the total mass of the photosensitive polyamic acid ester resin and the alkali-soluble polyfunctional group photosensitive epoxy resin; the mass of the low-temperature curing accelerator is 0.5-3% of the mass of the photosensitive polyamide acid ester resin; the preparation method of the photosensitive polyamic acid ester resin comprises the following steps: reacting dianhydride with diamine, and taking monoanhydride as an en