Primula sapphirina has a bell-shaped corolla that hangs downwards, lacks spherical hair tufts at the throat, and has shorter flower styles compared to Primula primulina.
The corolla is blue-purple, 4.5-6 mm long, with a short tube nearly equaling the calyx, and a limb diameter of 4-6 mm. The lobes are nearly square or slightly inverted-ovate to elliptic, 2-lobed at the apex.
The leaves are oblong to ovate-lanceolate, 5-10 mm long and 2-5 mm wide, blunt or rounded at the tip, gradually narrowing at the base. The margins are deeply toothed resembling pinnatifid, with sparse white short hairs or nearly glabrous on the upper surface, and short hairs along the midrib on the lower surface.