NOVELTY - A catalyst comprises (mass %) palladium (Pd) nanoparticles (15-20) as an active catalysis component, and titanium dioxide (TiO2)- carbon nanotube (CNT) composite as a carrier. The mass ratio of the TiO2 to the CNT is 1.5:1-2:1.    USE - A catalyst used for preparing an electrochemical fuel cell.    ADVANTAGE - The catalyst has high and stable electrochemical oxidization-reduction activity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparing the catalyst, comprising:    (A) placing CNT in a mixed acid of concentrated sulfuric acid and concentrated nitric acid, performing constant-temperature ultrasonic reaction for 6-8 hours at 80-100 degrees C, washing by deionized water, filtering until the pH of the filtrate is neutral, and drying at low temperature to obtain a functionalized CNT material;    (B) placing TiO2 powder in a muffle furnace, roasting at 500-700 degrees C, dispersing into 0.2-0.6M nitric acid after cooling, reacting for 1-3 hours under a stirring condition, washing by deionized water, filtering until the pH of the filtrate is neutral, and drying at 60-80 degrees C to obtain a modified TiO2 material;    (C) dispersing the modified TiO2 material in deionized water, stirring for 10-15 minutes at fast speed, adding the CNT material, continuing to stir for 20-30 minutes, slowly adding 15-25 mL isopropyl alcohol, continuing to stir for 20-40 minutes, adding 5-8 mL ethylene glycol, continuing to stir for 6-8 hours, washing and filtering until the alcohol substance is washed off completely, and drying to obtain the TiO2-CNT composite;    (D) dispersing palladium chloride (PdCl2) material having a weight of 10-30% of the weight of the TiO2-CNT composite in deionized water, and performing constant-temperature ultrasound for 20-30min at 50 degrees C to obtain uniform aqueous solution of PdCl2; and    (E) dispersing 50 mg TiO2-CNT composite in deionized water under the stirring condition, continuously and quickly stirring for 10-15 minutes, dropwise adding the aqueous solution of PdCl2, continuing to stir for 1-2 hours, slowly adding excess sodium borohydride, continuing to stir for 6-8 hours, washing and filtering, and drying.