The invention discloses a high-capacity formation lead paste. An anode lead paste comprises the raw materials of lead powder, deionized water, dilute sulphuric acid and anode auxiliary materials, and particularly comprises 100 parts by weight of lead powder, 6.6-7.4 parts by weight of dilute sulphuric acid, 10-11 parts by weight of deionized water, 3-5 parts by weight of red lead, 0.1-0.3 part by weight of aquadag, 0.08-025 part by weight of stannous mono-sulphate, 0.03-0.05 part by weight of bismuth trioxide, 0.03-0.05 part by weight of antimonous oxide and 0.06-0.1 part by weight of polyester staple fiber; and a cathode lead paste comprises the raw materials of lead powder, deionized water, dilute sulphuric acid and cathode auxiliary materials, and particularly comprises 100 parts by weight of lead powder, 6.5-8.5 parts by weight of dilute sulphuric acid, 9-10 parts by weight of deionized water, 0.5-0.8 part by weight of barium sulfate, 0.15-0.25 part by weight of acetylene carbon black, 0.30-0.40 part by weight of humic acid and 0.06-0.1 part by weight of polyester staple fiber. The invention also discloses a preparation method of the high-capacity formation lead paste.