A vehicle lamp optical assembly, comprising a primary optical unit group having a plurality of primary optical units (1, 2, 3) arranged side by side, wherein the primary optical unit (1, 2, 3) comprises a light entrance portion and a light guide portion (11, 21, 31), the light guide portion has a light entrance portion mounting surface and a primary light emission surface (111, 311), the light entrance portion mounting surface is provided with at least one light entrance portion, the light entrance portion is configured to enable incident light to be converged and emitted in a forwards direction to the light guide portion, and the light guide portion is configured to be capable of guiding the incident light to be emitted in the forwards direction from the primary light emission surface; and a secondary optical unit, wherein the secondary optical unit has a secondary light emission surface and a secondary light entrance surface corresponding to the primary light emission surface (111, 311), and the secondary light emission surface is a narrow and long smooth curved surface; characterised in that the light guide portions of the plurality of primary optical units in the primary optical unit group are connected into a whole, an auxiliary light source is provided on at least one side of the primary optical unit group in a left-right direction of the light guide portion, wherein the left-right direction is transverse to the forwards direction, and light emitted by the auxiliary light source enters from a side surface of the light guide portion and is emitted from the primary light emission surface; a light converging structure being provided between the auxiliary light source and the light guide portion. a primary optical unit group having a plurality of primary optical units (1, 2, 3) arranged side by side, wherein the primary optical unit (1, 2, 3) comprises a light entrance portion and a light guide portion (11, 21, 31), the light guide portion has a light entrance portion mounting surface and a primary light emission surface (111, 311), the light entrance portion mounting surface is provided with at least one light entrance portion, the light entrance portion is configured to enable incident light to be converged and emitted in a forwards direction to the light guide portion, and the light guide portion is configured to be capable of guiding the incident light to be emitted in the forwards direction from the primary light emission surface; and a secondary optical unit, wherein the secondary optical unit has a secondary light emission surface and a secondary light entrance surface corresponding to the primary light emission surface (111, 311), and the secondary light emission surface is a narrow and long smooth curved surface; characterised in that the light guide portions of the plurality of primary optical units in the primary optical unit group are connected into a whole, an auxiliary light source is provided on at least one side of the primary optical unit group in a left-right direction of the light guide portion, wherein the left-right direction is transverse to the forwards direction, and light emitted by the auxiliary light source enters from a side surface of the light guide portion and is emitted from the primary light emission surface; a light converging structure being provided between the auxiliary light source and the light guide portion.