The invention provides a portable soil available nutrient detection device which comprises a glass micro-electrode array, a pre-amplification device, a signal conditioning circuit and a data processing device. The glass micro-electrode array is used for converting the concentration of to-be-detected nutrients in to-be-detected soil nutrient liquid into original electric signals; the pre-amplification device is connected with the glass micro-electrode array and is used for amplifying the original electric signals to obtain enhanced electric signals; the signal conditioning circuit is connected with the pre-amplification device and is used for carrying out denoising processing on the enhanced electric signals to obtain effective electric signals; the data processing device is connected with the signal conditioning circuit and is used for converting and processing the effective electric signals. The portable soil available nutrient detection device has the advantage that adverse impact of interference signals on data analysis can be effectively reduced.