The preparation of angiotensin converting enzyme (ACE) inhibitory peptides from ovalbumin, the main protein in egg whites, can provide a reference for their value-added application. The desalination of crude enzymatic hydrolysates from ovalbumin in this paper was performed by ion exchange chromatography, using the following desalting conditions: room temperature (25 ℃), sample load of 20 mL, and flow rate of 8 BV/h. Under these conditions, the desalination rate of hydrolysates, nitrogen recovery rate, and ACE inhibition rate were 83.6%, 87.71%, and 80.31%, respectively. Two ultrafiltration membranes with molecular weight cut-offs of 10 ku and 3 ku were employed to separate the desalinated hydrolysates into three fractions: >10 ku, 3~10 ku, and <3 ku. The optimal operating conditions were as follows: ultrafiltration time of 40 min, operating pressure of 1.5 bar, and temperature of 35 ℃ for 10 ku or 30 ℃ for 3 ku. All three fractions showed ACE inhibitory activity, and the highest activity was found in the <3 ku fraction. Compared to crude hydrolysates, the total and surface hydrosulfuryl contents of the <3 ku fraction were significantly decreased (p < 0.05), the surface hydrophobicity was increased (p < 0.05), and thermal stability was improved. Therefore, desalination and ultrafiltration treatments can effectively reduce the salt content of crude enzymatic hydrolysates of ovalbumin and produce a fraction with high ACE inhibitory activity.