The invention provides a pesticide adopting D-limonene as a synergist. The pesticide contains: an effective amount of one or two of triazophos, avermectin, chlopyrifos, propargite, bifenthrin and lambda-cyhalothrin, and especially preferably an avermectin and triazophos combination, or avermectin or bifenthrin; an effective amount of a solvent for dissolving above pesticides, the solvent comprising the D-limonene; and an effective amount of an emulsifier. The synergistic pesticide utilizes the characteristic of high dissolving ability of D-limonene, uses the D-limonene as the solvent of avermectin and other pesticides, and utilizes the dissolving and destroying effects of D-limonene on the wax layer on the pest surfaces of pests to make the pesticides easily enter the pest bodies, so the quick effectiveness of the pesticide is increased, thereby the insecticidal is improved.