The invention relates to a plunger packing sealing and lubricating device of a reciprocating pump. The reciprocating pump comprises a pump body (16), wherein a pump cavity is formed in the pump body (16); the pump body (16) is connected with a box (15); a plunger passage is arranged in the box (15); a plunger (17) is arranged in the plunger passage of the box (15) and in the pump cavity of the pump body (16); seal packing is arranged between the plunger (17) and the inner wall of the plunger passage; the plunger packing sealing and lubricating device is characterized by further comprising an oil tank (1) filled with lubricating oil and an exchanging tank (21); the mounting position of the oil tank (1) is higher than the center line of the plunger (17); the oil tank (1) is communicated with the plunger passage in the box (15) through an oil supplementary pipeline; the mounting position of the exchanging tank (21) is lower than the center line of the plunger (17); and the exchanging tank (21) is communicated with the plunger passage in the box (15) through an exchanging pipeline. Compared with the prior art, the plunger packing sealing and lubricating device can prolong the service life of plunger packing and reduces power dissipation of friction.