A spinning disk reactor (SDR) operated in a continuous mode was adopted for producing silver nanoparticles, aiming at an increase in the production rate. Two protecting agents, i.e., poly(vinylpyrrolidone) (PVP) and hydroxypropylmethyl cellulose (HPMC), were tested, which have been proven to be effective in Our previous work of recycle operation. Using PVP as protecting agent, the effects of the operating variables, including the rotation speed, the feeding rate, the dosage of protecting agent, and reactant concentration, on the particle size and yield of the silver product were investigated. The experiment was further conducted using HPMC as protecting agent to compare the experimental results between the two protecting agents. The use of PVP gave smaller silver nanoparticles; however, a higher yield was obtained by using HPMC. Although the yield of continuous operation was lower than that of recycle operation, the production rate was much higher for either protecting agent, providing a great potential for commercialization.