Ultrashort laser pulses serve as essential tools for generating attosecond pulses and probing the microscopic world, making precise characterization of their temporal properties imperative. Existing characterization techniques are generally operated in the frequency and temporal domains. In the frequency domain methods, the temporal profiles and phases of ultrashort pulses are indirectly reconstructed from the spectra generated through nonlinear interactions; however, they require broad phase-matching bandwidths for the characterization of few-cycle pulses and often rely on complex iterative retrieval algorithms. Time-domain methods, which employ ultrafast temporal gates to directly sample the ultrashort pulse, offer more intuitive measurements but typically involve complicated optical setups and demand relatively high pulse intensities. Here, we propose an improved all-optical all-reflection sampling method based on third-order nonlinear effects with perturbation in the air. The method utilizes coaxial internal and external mirrors to split the input pulse into two components: a high-energy driving pulse from the larger internal mirror and a low-energy perturbation pulse from the external mirror. Both pulses are focused into the air to generate third-harmonic generation (THG) signals. The driving pulse produces a dominant THG signal. By adjusting the diameter of the incident beam, the intensity of the perturbation pulse is controlled to prevent from generating THG signals independently. Nevertheless, it can modulate the total THG signal by affecting the total electric field amplitude, thereby enabling perturbation-induced THG modulation. The internal mirror is fixed on an electronically controlled positioning stage, allowing for adjustable relative delay between the driving and perturbation pulses. By measuring the THG modulated signal as a function of delay, we reconstruct both the spectral and temporal characteristics of the perturbation pulse through a Fourier transform algorithm. The key advantages of this method include employing air as the nonlinear medium and avoiding transmissive optical elements, which is a significant benefit for ultrashort pulse measurements. The coaxial geometry ensures collinear propagation of the two beams, reducing the time jitter between the two beams and enhancing measurement stability. Using the THG signal as the ultrafast temporal gate relaxes the intensity requirements, and the modulation signal can be detected with a conventional spectrometer. Using this method, we characterized the pulse duration of a Ti:sapphire laser and compared the results with those obtained using the conventional transient-grating frequency-resolved optical gating (TG-FROG) device, finding good agreement. The proposed all-optical all-reflection ultrashort pulse temporal sampling method demonstrates a compact, stable configuration, making it suitable for the characterization of ultrashort pulses in the visible to mid-infrared spectral range.