Step 1: Enter the mobile phone mall and download the mobile banking client of CCB; Step 2: Click to enter the mobile banking client of CCB, enter the account name, password and verification code, and log in to the personal account; Step 3: Enter the "Investment and Financial Management" page; Step 4: Click "Bond Investment", and then select "Savings Bond" in "Bond Classification"; Step 5: Find "savings bonds (Electronic)", select a product, click to enter the details page, and then click the "Buy" button to buy. For different mobile banking clients, the page display may be different, but the process is roughly the same. After logging in, you will find the national debt on the investment and financial management page, and then choose the electronic national debt, and then buy the product for purchase. Just follow the instructions on the page to complete the operation. It should be noted that the purchase of electronic bonds must first open a personal bond custody account, and can only be purchased during the issuance period. Extended information: 1. National debt (national debt; Government loan, also known as national debt, is a creditor-debtor relationship formed by the state raising funds from the society based on its own credit and in accordance with the general principles of debt. National debt is a kind of government bond issued by the state, which is issued by the central government to raise financial funds. It is a creditor's right certificate issued by the central government to investors, promising to pay interest within a certain period of time and repay the principal at maturity. Because the issuer of national debt is the country, it has the highest credit and is recognized as the safest investment tool. China's national debt refers to the national debt issued by the Ministry of Finance on behalf of the central government, which is guaranteed by the national financial reputation. It has always been called "Phnom Penh bond", and cautious investors like to invest in government bonds. There are three types of national debt: voucher national debt, bearer from bond national debt and book-entry national debt. 2. The creditors of national debt can be citizens, legal persons or other organizations at home and abroad, or the government and international financial organizations of a certain country or region, while the debtors can only be countries in general. 3. The occurrence, alteration and elimination of the legal relationship of national debt mostly reflect the unilateral will of the state. Although the legal relationship of national debt is equal to other financial legal relationships, it shows a certain subordinate relationship compared with the general creditor-debtor relationship, which is more obvious in the legal relationship of domestic debt.