Lattice orientation detection techniques are crucial for two-dimensional materials as many unusual properties, such as electronic, optical, catalytic and magnetic properties, are closely related to particular lattice orientations. Herein, we propose a novel, low-cost and convenient detection technique, referred to as a single-line-scan power spectrum analysis (SPSA), which is established based on the power spectrum analysis of friction information that is extracted from an atomic-resolution lateral friction microscopy image. By analysing the characteristics of the friction information and the corresponding frequency spectrum obtained from the tribological surface of MoS2, we innovatively establish a relationship between the frequency characteristics and lattice orientation and ultimately propose our SPSA, which enables detection of the direct lattice orientation using the frequency characteristic values of an arbitrary line on an atomic image. The experimental results further verify the effectiveness and convenience of the SPSA process.