A lock assembly for a battery lock-up mechanism, characterized in that the battery lock-up mechanism further comprises a fixing assembly which is adapted to be connected to a new energy vehicle, the lock assembly comprising: a casing having a cylindrical shape which is opened at a bottom end, and having a through hole at a top end; characterized by further comprising a stop end plate, the stop end plate and the casing defining an accommodation space, a through-hole being formed in the stop end plate, and a first engaging portion being formed in an upper surface of the stop end plate; a central pull shaft, an adjustment block and a return spring that are accommodated in the accommodation space, wherein the central pull shaft has a locking section, an adjustment section and a stop portion between the locking section and the adjustment section, the locking section protrudes from the through hole of the casing, but the stop portion is limited inside the accommodation space, the locking section has a first connection structure, and the locking section has a first engaging structure; the adjustment block comprises a flange portion and an extension portion extending from a lower side face of the flange portion, a second engaging portion is formed on a lower side face of the flange portion, a through hole having a second engaging portion is formed longitudinally extending through the flange portion and the extension portion of the adjustment block, and the extension portion protrudes out of the accommodation space from the through hole of the stop end plate for facilitating operation, the return spring is sleeved over the adjustment section of the central pull shaft for urging the adjustment block towards the stop end plate; and the first engaging portion is adapted to engage with the second engaging portion for restricting a relative rotation of the stop end plate and the adjustment block in a circumferential direction in an indexed manner, the first engaging structure engages with the second engaging structure and restricts a relative rotation of the central pull shaft and the adjustment block in the circumferential direction, and the first connection structure is adapted to engage with the second connection structure on the fixing assembly for restricting a relative axial movement of the fixing assembly and the lock assembly. a casing having a cylindrical shape which is opened at a bottom end, and having a through hole at a top end; characterized by further comprising a stop end plate, the stop end plate and the casing defining an accommodation space, a through-hole being formed in the stop end plate, and a first engaging portion being formed in an upper surface of the stop end plate; a central pull shaft, an adjustment block and a return spring that are accommodated in the accommodation space, wherein the central pull shaft has a locking section, an adjustment section and a stop portion between the locking section and the adjustment section, the locking section protrudes from the through hole of the casing, but the stop portion is limited inside the accommodation space, the locking section has a first connection structure, and the locking section has a first engaging structure; the adjustment block comprises a flange portion and an extension portion extending from a lower side face of the flange portion, a second engaging portion is formed on a lower side face of the flange portion, a through hole having a second engaging portion is formed longitudinally extending through the flange portion and the extension portion of the adjustment block, and the extension portion protrudes out of the accommodation space from the through hole of the stop end plate for facilitating operation, the return spring is sleeved over the adjustment section of the central pull shaft for urging the adjustment block towards the stop end plate; and the first engaging portion is adapted to engage with the second engaging portion for restricting a relative rotation of the stop end plate and the adjustment block in a circumferential direction in an indexed manner, the first engaging structure engages with the second engaging structure and restricts a relative rotation of the central pull shaft and the adjustment block in the circumferential direction, and the first connection structure is adapted to engage with the second connection structure on the fixing assembly for restricting a relative axial movement of the fixing assembly and the lock assembly.