The invention relates to phenolic resin glue containing a potassium ion alkali compound and a preparation method thereof. The phenolic resin glue containing the potassium ion alkali compound comprises the following components in percentage by weight: 19-23.5wt% of phenol, 36.5-41.5% of industrial formaldehyde with weight concentration of 37%, 0.8-12wt% of potassium ion alkali compound, 0-12wt% of extender and the balance of solvent. The preparation method comprises the following processing steps: 1) taking the components; 2) preparing the potassium ion alkali compound into solution with the weight concentration of 30% or 50%; 3) starting a stirrer, placing phenol, potassium ion alkali compound, formaldehyde with the weight concentration of 37%, extender and solvent into a reaction vessel, performing reaction for 1-3 hours, cooling to the temperature below 40 DEG C, and discharging, so that the phenolic resin glue containing the potassium ion alkali compound is obtained, wherein solid content of the phenolic resin glue is 36.5-45wt%, and viscosity determined under the condition of coating four cups of the phenolic resin is 17-90 seconds. The phenolic resin glue containing the potassium ion alkali compound has the advantages that bonding strength is high, cost is low (phenol raw material amount is less), content of free phenol and free formaldehyde in the phenolic resin glue containing the potassium ion alkali compound is low, environmental performance is good, and the traditional phenolic resin glue can be replaced.