The parameter control method is utilized to carry out the experimental investigation for the single pulse laser drilling of aluminum alloy 5052 sheets. Effects of pulse width, pulse recurrence frequency, and defocusing amount on microhole formation characteristics for laser drilling are achieved and the reasonable process parameter ranges are obtained, which can be the technical reference of process optimization and parameter selection for the pulsed laser drilling of aluminum alloy 5052. It shows that the laser pulse width can obviously influence the microhole diameter. Besides, the alteration of the pulse recurrence frequency may also result in the change of the drilled microhole diameter, that is, the entry hole diameter increases with the pulse repetition frequency. However, the radial size alteration for the exit hole shows a reverse trend. In addition, less tapered microholes with relatively small diameters can be drilled through appropriately decreasing pulse repetition frequency, reducing defocusing amount, and increasing pulse width.