Based on field data of nutrients observed in Laizhou Bay during May and August 2018, using the methods of nutrient restriction and potential eutrophication assessment standards, the distribution characteristics of nitrogen, phosphorus, and silicate in the Laizhou Bay were analyzed and discussed. The results showed that the concentrations of DIN ranged from 1.64 μmol/L to 106.36 μmol/L with an average content of 24.18 μmol/L and were significantly higher in May. The concentrations of PO34–-P ranged from “not detected” to 2.010 μmol/L with an average content of 0.182 μmol/L, and were significantly higher in August. The concentrations of SiO23–-Si ranged from 0.97 μmol/L to 78.93 μmol/L with an average content of 18.30 μmol/L and were also significantly higher in August. The areas with higher values for DIN, PO34–-P, and N/P ratio were mainly located within the sea area near the Xiaoqing River and Yellow River estuaries in the west of Laizhou Bay. The areas with higher values for SiO23–-Si、Si/N ratio, and Si/P ratio were mainly located at the bottom of Laizhou Bay and near the coast of Longkou-Laizhou. The nutrient structure analysis indicated that availability of PO34–-P was limited in May and August while that of SiO23–-Si was limited in May. The spatial distribution of nutrients in the Laizhou Bay was mainly influenced by the terrestrial inputs, especially during periods of high water levels. This observation aligns with the higher nutrient content of the Xiaoqing River and Yellow River estuaries. SiO23–-Si and PO34–-P were the main limiting factors of primary productivity in May, while DIN and PO34–-P were the main limiting factors of primary productivity in August. The horizontal distribution of nutrient structure restriction indicated that it was easy to cause red tide in Laizhou-Zhaoyuan culture area in spring and Dongying-Weifang culture area in summer. The limited primary productivity in the Laizhou-Zhaoyuan area during summer could substantially influence the aquaculture in this area.