NOVELTY - A heterojunction structure of shape-controlled metal nanocrystalline/carbon nanotube is prepared by dispersing 0.01-0.5 g carbon nanotube (2) in absolute ethanol solution under room temperature and performing ultrasonic processing; dropping solution on conductive substrate to uniformly distribute carbon nanotube, and drying; using graphite electrode (3) as auxiliary electrode and conductive substrate with carbon nanotube distributed on surface as working electrode at room temperature; and rinsing deposited nanotube heterojunction structure with deionized water and absolute ethanol and drying.    USE - Method for preparing heterojunction structure of shape-controlled metal nanocrystalline/carbon nanotube (claimed) for fuel battery and electrochemistry catalysis.    ADVANTAGE - The method is simple, and has easy to obtain material, quick reaction and short preparing period. The prepared nanotube has shape of irregular sphere, hexagonal sheet, truncated cube and octahedron which can be prepared by only changing depositing current density.    DETAILED DESCRIPTION - The heterojunction structure of shape-controlled metal nanocrystalline/carbon nanotube is prepared by:    (A) rinsing conductive substrate (1) with absolute ethanol and drying;    (B) dispersing 0.01-0.5 g carbon nanotube (2) in absolute ethanol solution under room temperature and performing ultrasonic processing for 10-30 minutes;    (C) dropping solution on conductive substrate to uniformly distribute carbon nanotube, and drying;    (D) dissolving soluble metal salt (0.1-0.5 M) and boric acid (0.1-0.5 M) into deionized water and constantly mixing to prepare electrolyte (4);    (E) using graphite electrode (3) as auxiliary electrode and conductive substrate with carbon nanotube distributed on surface as working electrode at room temperature;    (F) pouring electrolyte in glass container and depositing in constant current mode;    (G) measuring voltage and current in depositing process with voltmeter (6) and ammeter, where depositing current density is 0.06-6.00 mA/cm2 and depositing time is 5-60 seconds; and    (H) rinsing deposited heterojunction structure of metal nanocrystalline/carbon nanotube with deionized water and absolute ethanol and drying in air.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic diagram showing a method for preparing the shape-controlled metal nanocrystalline/carbon nanotube.    Conductive substrate (1)    Carbon nanotube (2)    Graphite electrode (3)    Electrolyte (4)    Voltmeter (6)